configure.ac: remove spurious ","
configure.ac: remove spurious ","

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

nicolasvasilache/isl,epowers/isl,serge-sans-paille/isl,serge-sans-paille/isl,cfx-next/toolchain_isl-upstream,VanirLLVM/toolchain_isl,cfx-next/toolchain_isl-upstream,simbuerg/isl,epowers/isl,UBERTC/isl,jleben/isl,cfx-next/toolchain_isl-upstream,Meinersbur/isl,VanirLLVM/toolchain_isl,BenzoSM/isl,pierrotdelalune/isl,inducer/isl-mirror,PollyLabs/isl,jleben/isl,tobig/isl,abduld/isl,evaautomation/isl,nicolasvasilache/isl,BenzoSM/isl,cfx-next/toolchain_isl-upstream,SaberMod/isl-current,simbuerg/isl,Distrotech/isl,BenzoSM/isl,Distrotech/isl,epowers/isl,BobSaget-Mod/libisl,UBERTC/isl,simbuerg/isl,nicolasvasilache/isl,SaberMod/isl-current,serge-sans-paille/isl,pierrotdelalune/isl,crossbuild/isl,epowers/isl,jleben/isl,serge-sans-paille/isl,pierrotdelalune/isl,abduld/isl,KangDroidSMProject/ISL,Distrotech/isl,jleben/isl,cfx-next/toolchain_isl-upstream,PollyLabs/isl,BobSaget-Mod/libisl,KangDroidSMProject/ISL,simbuerg/isl,tobig/isl,BobSaget-Mod/libisl,abduld/isl,BobSaget-Mod/libisl,inducer/isl-mirror,pierrotdelalune/isl,jleben/isl,Distrotech/isl,pierrotdelalune/isl,PollyLabs/isl,BobSaget-Mod/libisl,inducer/isl-mirror,simbuerg/isl,epowers/isl,crossbuild/isl,crossbuild/isl,crossbuild/isl,Meinersbur/isl,PollyLabs/isl,nicolasvasilache/isl,UBERTC/isl,Meinersbur/isl,inducer/isl-mirror,KangDroidSMProject/ISL,inducer/isl-mirror,evaautomation/isl,serge-sans-paille/isl,VanirLLVM/toolchain_isl,nicolasvasilache/isl,evaautomation/isl,KangDroidSMProject/ISL,UBERTC/isl,SaberMod/isl-current,evaautomation/isl,tobig/isl,VanirLLVM/toolchain_isl,Distrotech/isl,KangDroidSMProject/ISL,BenzoSM/isl,Meinersbur/isl,abduld/isl,PollyLabs/isl,SaberMod/isl-current,tobig/isl,VanirLLVM/toolchain_isl,BenzoSM/isl