Windows: Runner fails with commit message starts with non ASCII character

Summary

We had today the first error with a runner. The runner seems to have problems with commit messages, that starts with non ASCII char.

Steps to reproduce

Create a commit, that starts with German special characters (e.g. Ändern der Versionsnummer in der WebApi). Push it, to start the pipeline.

Actual behavior

Pipeline failes.

Expected behavior

Pipeline run.

Relevant logs and/or screenshots

Origin commit message: Ändern der Versionsnummer in der WebApi

Runner log:

Running with gitlab-runner 11.0.0 (5396d320)
  on Windows runner on Win2016 f4aded2c
Using Shell executor...
Running on DEVBUILD...
In C:\Users\ba\AppData\Local\Temp\build_script058296123\script.ps1:91 Zeichen:23
+ $CI_COMMIT_MESSAGE="�"ndern der Versionsnummer in der WebApi`n"
+                       ~~~~~
Unerwartetes Token "ndern" in Ausdruck oder Anweisung.
    + CategoryInfo          : ParserError: (:) [], ParseException
    + FullyQualifiedErrorId : UnexpectedToken
 
ERROR: Job failed: exit status 1

Environment description

• OS: Windows Server 2016

Used GitLab Runner version

Running with gitlab-runner 11.0.0 (5396d320)
  on Windows runner on Win2016 f4aded2c
Using Shell executor...