abuild: reset $install for sub packages

fixes #22

abuild

@@ -795,9 +795,10 @@ if [ -z "$newname" ]; then
 	. "$APKBUILD"
 fi
 
-# If we are handling a sub package then reset subpackages
+# If we are handling a sub package then reset subpackages and install
 if [ -n "$subpkgname" ]; then
 	subpackages=
+	install=
 fi
 
 trap 'die "Aborted by user"' INT