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)