Fix INetURLObject::operator==() when comparing paths

Regression from

    commit 43a6b595
    Date:   Mon Jul 10 12:42:24 2017 +0200

        simplify some OUString compareTo calls

        to either startsWith or == or !=

aPath2.startsWith(aPath1) is not the same as
aPath1.compareTo(aPath2, nLength) == 0
if aPath1 is longer than aPath2 ...

The consequence was a broken Macro Security Trusted Location that never
matched.

Change-Id: I6b7adab42982c020f3677bf24f18edd14210ffdf

tools/source/fsys/urlobj.cxx

@@ -3694,7 +3694,7 @@ bool INetURLObject::operator ==(INetURLObject const & rObject) const
                 default:
                     return false;
             }
-            return aPath2.startsWith(aPath1);
+            return aPath1.compareTo(aPath2, nLength) == 0;
         }
 
         default: