roll_util: Fix gitwatcher regex

Bug: b/243177456
Change-Id: I73b8fc650fb57a05f18011719e38645138a2e254
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/108731
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Reviewed-by: Ted Pudlik <tpudlik@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/recipe_modules/roll_util/api.py b/recipe_modules/roll_util/api.py
index 775b4a8..f20e7e1 100644
--- a/recipe_modules/roll_util/api.py
+++ b/recipe_modules/roll_util/api.py
@@ -44,7 +44,7 @@
     'Cq-Cl-Tag:',
     'Fixed:',
     'Fixes:',
-    re.compile(r'Git[ -]watcher:', re.IGNORECASE),
+    re.compile(r'Git[ -]?watcher:', re.IGNORECASE),
     'No-Docs-Update-Reason:',
     'No-Presubmit:',
     'No-Tree-Checks: true',