Fixed signed/unsigned comparison warning

--HG--
branch : 3.3
extra : source : 030fda7b1de8c76c9f5c61bf73041068ba341c2b
Issue #16233: When the module browser is not invoked in an editor window with
a filename, pop up the Open Module box. If a module is opened, open a
corresponding browser.

--HG--
branch : 3.4
Merge with 3.4 Issue#16233
Merge 3.3

--HG--
branch : 3.4
merge 3.4