Fix LanguageAssistant problem when UtBot plugin running from directory

[tamarinvs19]

Description

LanguageAssistant class cannot find which language assistant (JVM / Python / JS) should be started when you run it from right-click menu on directory.

Type of Change

• Bug fix: fixed this problem, now this function works successfully

How Has This Been Tested?

Manual Scenario

1. Open IntelliJ IDEA
2. Open Java project
3. In Project window make right click on directory where exists java-files
4. Choose "Generate Tests with UnitTestBot..."
5. UI UnitTestBot window should open

Checklist (remove irrelevant options):

• Self-review of the code is passed
• The change contains enough commentaries, particularly in hard-to-understand areas
• No new warnings
• All tests pass locally with my changes