Fix for uninitialized "root" variable

[iljalukin]

This entry appears in the error log while testing rewrite rules: using uninitialized "root" variable. The $root variable declared in the previous location is apparently out of scope here and would probably be better declared in the server scope.

[mjansenDatabay]

@tmuellerdatabay Could you please review this?

[tmuellerdatabay]

@mjansenDatabay you can merge this.