build-unit-test-docker: escape topic queries

Gerrit topics can contain spaces[1].  We need to escape those so
that the http request can be done successfully.

[1]: https://gerrit.openbmc.org/c/openbmc/entity-manager/+/83520

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I934a012497eb4e33ee606f133f2f705b8e5fcd10
diff --git a/scripts/build-unit-test-docker b/scripts/build-unit-test-docker
index a1e0312..db248fe 100755
--- a/scripts/build-unit-test-docker
+++ b/scripts/build-unit-test-docker
@@ -471,10 +471,13 @@
         if gerrit_project == self.package and gerrit_rev:
             return False
 
+        # URL escape any spaces.  Gerrit uses pluses.
+        gerrit_topic_escape = urllib.parse.quote_plus(gerrit_topic)
+
         try:
             commits = json.loads(
                 urllib.request.urlopen(
-                    f"https://gerrit.openbmc.org/changes/?q=status:open+project:{self.package}+topic:{gerrit_topic}"
+                    f'https://gerrit.openbmc.org/changes/?q=status:open+project:{self.package}+topic:"{gerrit_topic_escape}"'
                 )
                 .read()
                 .splitlines()[-1]