Improved ccache parse-config to check if we build with debug symbols

- enabling ccache while building a package with debug symbols is
  senseless and just a waste of disk space

develop/ccache/parse-config

@@ -19,6 +19,8 @@ elif [ -z "`type -p ccache`" ]; then
 	echo_warning 'Compiler cache disabled! (ccache not available)'
 elif [ "$pkg" == gcc ]; then
 	echo_warning 'Compiler cache disabled! (package incompatible)'
+elif [ "$SDECFG_DEBUG" == 1 ]; then
+	echo_warning 'Compiler cache disabled! (package build with debug symbols)'
 else
 	unset ${!CCACHE_*}