science/gromacs: Use https for MASTER_SITES and GCC for build

- Switch MASTER_SITES to https
- Fails to build with LLVM 14-17, use GCC instead

Reference:
https://github.com/Homebrew/homebrew-core/blob/c3174cdd90e026ce95010b725aa0a2f312d41bcd/Formula/g/gromacs.rb

PR:		274435
Reviewed by:	yuri (maintainer)