git cl: add temporary workaround for u200 chars in PolyGerrit.

(edited, so that next next line gets u200 char 
between R= and reviewer email)

R=​​mstarzinger@chromium.org
TBR=agable@chromium.org
BUG=b/34702620 (internal)

Change-Id: I58f2528dd28e3a43d8eb2d7d4f5c046460d8a9ee
Reviewed-on: https://chromium-review.googlesource.com/440085
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>

git_cl.py

@@ -2799,7 +2799,12 @@ class _GerritChangelistImpl(_ChangelistCodereviewBase):
 
     reviewers = change_desc.get_reviewers()
     if reviewers:
-      refspec_opts.extend('r=' + email.strip() for email in reviewers)
+      # TODO(tandrii): remove this horrible hack once (Poly)Gerrit fixes their
+      # side for real (b/34702620).
+      def clean_invisible_chars(email):
+        return email.decode('unicode_escape').encode('ascii', 'ignore')
+      refspec_opts.extend('r=' + clean_invisible_chars(email).strip()
+                          for email in reviewers)
 
     if options.private:
       refspec_opts.append('draft')