fix version parsing bug in "ipkg upgrade"

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@355 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/default/target_skeleton/bin/ipkg

@@ -21,8 +21,8 @@ set -o noglob
 
 ipkg_is_upgrade () {
   local A B a b
-  A=$(echo $1 | sed "s/[0-9]*/ & /g")
-  B=$(echo $2 | sed "s/[0-9]*/ & /g")
+  A=$(echo $1 | sed "s/[0-9]*/ & /g" | sed "s/[^ A-Za-z0-9]//g")
+  B=$(echo $2 | sed "s/[0-9]*/ & /g" | sed "s/[^ A-Za-z0-9]//g")
   while [ \! -z "$A" ] && [ \! -z "$B" ]; do {
     set $A; a=$1; shift; A=$*
     set $B; b=$1; shift; B=$*