chore: update gmp api url for stagenet

Author: nrsirapop

.env.stagenet

@@ -6,7 +6,7 @@ NEXT_PUBLIC_STATUS_MESSAGE=
 NEXT_PUBLIC_ENVIRONMENT=stagenet
 
 NEXT_PUBLIC_API_URL=https://stagenet.api.axelarscan.io
-NEXT_PUBLIC_GMP_API_URL=
+NEXT_PUBLIC_GMP_API_URL=https://stagenet.api.gmp.axelarscan.io
 NEXT_PUBLIC_RPC_URL=http://k8s-stagenet-axelarco-bcdb269e08-d3015352a090f6b0.elb.us-east-2.amazonaws.com:26657
 NEXT_PUBLIC_LCD_URL=http://k8s-stagenet-axelarco-bcdb269e08-d3015352a090f6b0.elb.us-east-2.amazonaws.com:1317