glibc: build with --enable-obsolete-nsl
glibc: build with --enable-obsolete-nsl

needed to make sure libnsl's headers are installed once again, for the full
details, please refer to #7846 .

Closes: #7928 [via git-merge-pr]

necrophcodr/void-packages,EaterOfCode/void-packages,liwakura/void-packages,coredumb/void-packages,EaterOfCode/void-packages,juliendehos/void-packages,ayghor/void-packages,ayghor/void-packages,floGik/void-packages,juliendehos/void-packages,floGik/void-packages,NeoChontrix/void-packages,liwakura/void-packages,NeoChontrix/void-packages,juliendehos/void-packages,opsaaspo/void-packages,coredumb/void-packages,EaterOfCode/void-packages,kulinacs/void-packages,kulinacs/void-packages,opsaaspo/void-packages,ayghor/void-packages,NeoChontrix/void-packages,liwakura/void-packages,coredumb/void-packages,NeoChontrix/void-packages,liwakura/void-packages,coredumb/void-packages,floGik/void-packages,ayghor/void-packages,necrophcodr/void-packages,kulinacs/void-packages,ayghor/void-packages,floGik/void-packages,juliendehos/void-packages,NeoChontrix/void-packages,opsaaspo/void-packages,juliendehos/void-packages,floGik/void-packages,coredumb/void-packages,necrophcodr/void-packages,juliendehos/void-packages,floGik/void-packages,coredumb/void-packages,opsaaspo/void-packages,NeoChontrix/void-packages,kulinacs/void-packages,EaterOfCode/void-packages,liwakura/void-packages,EaterOfCode/void-packages,necrophcodr/void-packages,opsaaspo/void-packages,kulinacs/void-packages,opsaaspo/void-packages,kulinacs/void-packages,necrophcodr/void-packages,ayghor/void-packages,liwakura/void-packages