Divide by zero in althea chain test runner when the base fee is zero

[ChristianBorst]

Finished release [optimized] target(s) in 0.17s                                                                                                                                           
 Running `/althea/integration_tests/target/release/test-runner`                                                                                                                           

[2023-02-27T18:01:47Z INFO test_runner] Starting Althea test-runner
[2023-02-27T18:01:47Z INFO test_runner::bootstrapping] found erc20 address it is 0x0412C7c846bb6b7DC462CF6B453f76D8440b2609
[2023-02-27T18:01:47Z INFO test_runner::bootstrapping] found erc20 address it is 0x30dA8589BFa1E509A319489E014d384b87815D89
[2023-02-27T18:01:47Z INFO test_runner::bootstrapping] found erc20 address it is 0x9676519d99E390A180Ab1445d5d857E3f6869065
[2023-02-27T18:01:47Z INFO test_runner::bootstrapping] found erc721 address it is 0xD7600ae27C99988A6CD360234062b540F88ECA43
thread 'main' panicked at '(bnum) attempt to divide by zero', /root/.cargo/registry/src/github.com-1ecc6299db9ec823/bnum-0.5.0/src/buint/wrapping.rs:172:1
stack backtrace:
0: 0x564a2ecd87ca - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h3614b94d23504059
1: 0x564a2ecfcb2e - core::fmt::write::hb4129b557c4e9a1b
2: 0x564a2ecd2ab5 - std::io::Write::write_fmt::h1ae6291e6cd38aa9
3: 0x564a2ecd8595 - std::sys_common::backtrace::print::h43f60710c8165538
4: 0x564a2ecd9d7f - std::panicking::default_hook::{{closure}}::he0dd184d46c14d15
5: 0x564a2ecd9abb - std::panicking::default_hook::h207a360985428f53
6: 0x564a2ecda48c - std::panicking::rust_panic_with_hook::h4649945143162e2d
7: 0x564a2ecda1e2 - std::panicking::begin_panic_handler::{{closure}}::h40d5f84a6649f842
8: 0x564a2ecd8c7c - std::sys_common::backtrace::__rust_end_short_backtrace::h9c0a2c39c73dcc32
9: 0x564a2ecd9f32 - rust_begin_unwind
10: 0x564a2e6d1263 - core::panicking::panic_fmt::hea8d6e12bbaca8d1
11: 0x564a2ecb0f64 - <num256::uint256::Uint256 as core::ops::arith::Div>::div::h22d3b62a43033ff4
12: 0x564a2e844d44 - web30::client::Web3::simulated_gas_price_and_limit::{{closure}}::hb4d1a2f866752e77
13: 0x564a2e83ee82 - web30::erc20_utils::::get_erc20_balance::{{closure}}::h99a8cca8199f8de1
14: 0x564a2e84a9ba - test_runner::main::{{closure}}::h398469cd1aa59bbb
15: 0x564a2e81367b - std::thread::local::LocalKey::with::h24bdda5c3bf21bec
16: 0x564a2e72a1aa - <core::pin::Pin

as core::future::future::Future>::poll::hcfef7d49130ea8ba
17: 0x564a2e9558e7 - tokio::runtime::scheduler::current_thread::CurrentThread::block_on::hd1985c3b24bd37e6
18: 0x564a2e7277b7 - tokio::runtime::runtime::Runtime::block_on::hd9e94c12dab53d7e
19: 0x564a2e956ff8 - test_runner::main::h7baba2d7b77eb375
20: 0x564a2e737a83 - std::sys_common::backtrace::__rust_begin_short_backtrace::ha5ff7657b95e1c00
21: 0x564a2e7ac589 - std::rt::lang_start::{{closure}}::hfef6a42456bf1da0
22: 0x564a2ecce2ac - std::rt::lang_start_internal::h347e99cc0feccf63
23: 0x564a2e957055 - main
24: 0x7fbf7df6a510 - __libc_start_call_main
25: 0x7fbf7df6a5c9 - __libc_start_main@GLIBC_2.2.5
26: 0x564a2e6d1885 - _start
27: 0x0 -