gdb: add missing zlib dependency

Signed-off-by: Florian Fainelli <florian@openwrt.org>

SVN-Revision: 34256

package/devel/gdb/Makefile

@@ -30,7 +30,7 @@ endef
 define Package/gdb
 $(call Package/gdb/Default)
   TITLE:=GNU Debugger
-  DEPENDS+=+libreadline +libncurses
+  DEPENDS+=+libreadline +libncurses +zlib
 endef
 
 define Package/gdb/description