MAFFT validation initiates never-ending recursive calling of cmd.exe

Sometimes, adding external tools initiates never-ending recursive calling of cmd.exe.

The previous time this problem was spotted with the 32-bit version of the external tools package.

Scenario:

1. Remove "UGENE.ini".
2. Start UGENE and add 32 bit external tools.
   Expected result: the validation is successful.
   Actual result: there is a tree of recursive calls of "cmd.exe" in "process explorer" or similar tool. The Windows system hangs, so that restarting is required.