tbb/tbb.h check in configure.ac passes when tbb/ttb.h is absent on Fedora

[rsbivand]

proxyC/configure.ac

Lines 27 to 29 in a7402a5

	AC_CHECK_HEADER([tbb/tbb.h],
	[TBBFLAGS=-DTBB;TBBLIBS=-ltbb],
	[AC_MSG_WARN([parallel computing is disabled because tbb/tbb.h (Intel TBB) is not found])])

See quanteda/quanteda#2364 for analysis and quanteda/quanteda#2368 for resolution.

Use of TBB really is not a good idea, there are other alternatives, and use assumes that you know what other work the machine is doing.

[koheiw]

@rsbivand thanks for the PR for quanteda. I will incorporate your configure.ac to proxyC too!

[barracuda156]

It is not only on Fedora, existing configure does not check for OneTBB at all :)