libiconv: Add libintl dependency
libiconv: Add libintl dependency

Without it, build is failing to generate executable.
Hidden dependencies are frustrating.

This also makes sure the libintl symbols are expected without
'libintl_' prefix, like in all MSYS modules which use it.

atom2013/MSYS2-packages,mati865/MSYS2-packages,juergenpf/MSYS2-packages,atom2013/MSYS2-packages,mati865/MSYS2-packages,mati865/MSYS2-packages,atom2013/MSYS2-packages,JPeterMugaas/MSYS2-packages,JPeterMugaas/MSYS2-packages,waterlan/MSYS2-packages,waterlan/MSYS2-packages,waterlan/MSYS2-packages,juergenpf/MSYS2-packages,Alexpux/MSYS2-packages,Alexpux/MSYS2-packages,mati865/MSYS2-packages,Alexpux/MSYS2-packages,JPeterMugaas/MSYS2-packages,Alexpux/MSYS2-packages,atom2013/MSYS2-packages,juergenpf/MSYS2-packages,juergenpf/MSYS2-packages,JPeterMugaas/MSYS2-packages,waterlan/MSYS2-packages,juergenpf/MSYS2-packages