Fix change log generation in push-to-trunk script.

tools/push-to-trunk/common_includes.py

Index: tools/push-to-trunk/common_includes.py
diff --git a/tools/push-to-trunk/common_includes.py b/tools/push-to-trunk/common_includes.py
index 196593758e16d87f91da8acb2f0c26d74aa3d737..a2f0748f509be54ae8c3091b8529793a3787410f 100644
--- a/tools/push-to-trunk/common_includes.py
+++ b/tools/push-to-trunk/common_includes.py
@@ -105,7 +105,7 @@ def MakeChangeLogBody(commit_messages, auto_format=False):
     title = title.strip()
     if auto_format:
       # Only add commits that set the LOG flag correctly.
-      log_exp = r"^[ \t]*LOG[ \t]*=[ \t]*(?:Y(?:ES)?)|TRUE"
+      log_exp = r"^[ \t]*LOG[ \t]*=[ \t]*(?:(?:Y(?:ES)?)|TRUE)"
       if not re.search(log_exp, body, flags=re.I | re.M):
         continue
       # Never include reverts.