fix template (issue 654)

[allaVolkov]

fix template (issue 654)

Checklist

• Code compiles correctly
• Relevant tests were added (unit / contract / integration)
• Relevant logs were added
• Formatting and linting run locally successfully
• All tests pass
• UA review
• Design is documented
• Extended the README / documentation, if necessary
• Open source is approved

[allaVolkov]

The pull request fixes issue #654.
For specific Windows/make/cmd installation GNU Make wrongly parsed the following command in generated Makefile.mta:
mbt gen mtar -t=${t} --mtar=${mtar} --target_provided=${target_provided} {{- ExtensionsArg "-e"}}
Flag t (target) received the value of target path concatenated with the successor --mtar=...
This problem didn't raise in GitBush of the same consumer and was not reproducible in other environments.
The change fixed it for the problematic environment and didn't cause any regression in others.