Fix a typo in libtool, seems to be related to bug #742678

diff -up net-snmp-5.7.1/ltmain.sh.orig net-snmp-5.7.1/ltmain.sh
--- net-snmp-5.7.1/ltmain.sh.orig	2011-09-28 06:53:47.000000000 +0200
+++ net-snmp-5.7.1/ltmain.sh	2011-10-04 09:48:11.022131513 +0200
@@ -8051,7 +8051,7 @@ EOF
 	    elif test -n "$runpath_var"; then
 	      case "$perm_rpath " in
 	      *" $libdir "*) ;;
-	      *) func_apped perm_rpath " $libdir" ;;
+	      *) func_append perm_rpath " $libdir" ;;
 	      esac
 	    fi
 	  done