fix some tiny typos that caused errors in prod

bridge/__init__.py

@@ -278,7 +278,7 @@ def gitea_handle_issue_action():
         ])
 
         github_comment_post_result = github.post(
-            "https://api.github.com/repos/{}/{}/issues/{}/comment".format(
+            "https://api.github.com/repos/{}/{}/issues/{}/comments".format(
                 repo_owner,
                 repo_name,
                 issue_number,

bridge/utils.py

@@ -13,4 +13,4 @@ def from_base64(s: str) -> str:
 issue_sentinel = "GITEA_GITHUB_ISSUE_SYNC_SENTINEL"
 
 def generate_sentinel(url: str) -> str:
-    return ' '.join([sentinel, to_base64(url)])
+    return ' '.join([issue_sentinel, to_base64(url)])