Server 500 with redmine_pivot_table

[DarkSideGeek]

I filed a bug with redmine_pivot_table. PivotTable works fine on its own, but in conjunction with CategoryTree it generates a 500 error.

https://github.com/deecay/redmine_pivot_table/issues/13

The author seemed disinclined to investigate and suggested:

The conflict might be caused by category-tree using a custom defined function in
queries_helper_patch, which other plugins with similar patch don't do. But I can't
be sure.

If I really wanted both plugins to coexist, I would try to transplant the contents of 
the function render_issue_category_with_tree into queries_helper_patch.rb, to 
eliminate custom function call.

Thought I might bring it up here to see if there was a way to fix without hacking something non-portable?