fix use of older omf_use in omf_remove_package

pkg/omf/cli/omf_remove_package.fish

@@ -18,7 +18,7 @@ function omf_remove_package
         return $OMF_INVALID_ARG
       end
       if test $pkg = (cat $OMF_CONFIG/theme)
-        omf_use "default"
+        omf_theme "default"
       end
       rm -rf $OMF_PATH/themes/$pkg
     end
@@ -29,4 +29,4 @@ function omf_remove_package
     end
   end
   refresh
-end
\ No newline at end of file
+end