warnings: stop variable shadowing

warnings: stop variable shadowing

Rename local variables not to conflict at following locations:

asn.c:160:26: warning: declaration of 'txtrec' shadows a global declaration [-Wshadow]
dns.c:351:50: warning: declaration of 'af' shadows a global declaration [-Wshadow]
dns.c:89:40: warning: declaration of 'af' shadows a global declaration [-Wshadow]
gtk.c:213:31: warning: declaration of 'Entry' shadows a global declaration [-Wshadow]
net.c:1408:31: warning: declaration of 'host' shadows a global declaration [-Wshadow]
net.c:1726:38: warning: declaration of 'af' shadows a global declaration [-Wshadow]
net.c:1744:39: warning: declaration of 'af' shadows a global declaration [-Wshadow]
net.c:876:7: warning: declaration of 'sequence' shadows a global declaration [-Wshadow]