frontend: better clone_url matching on webhooks

Previously we just dropped ".git" suffix from git_cloneurl before
comparison, but not the trailing slashes.  We also did just
'rstrip(".git")', which would also remove strings like "tig.git",
potentially leading false-positive matches.

Fixes: #2772

frontend/coprs_frontend/coprs/logic/packages_logic.py

@@ -168,11 +168,16 @@ def get_or_create(cls, copr_dir, package_name, src_pkg):
         db.session.add(package)
         return package
 
+    @classmethod
+    def _normalize_git_clone_url(cls, clone_url):
+        normalized = clone_url.rstrip("/")
+        return normalized.removesuffix(".git")
+
     @classmethod
     def get_for_webhook_rebuild(
         cls, copr_id, webhook_secret, clone_url, commits, ref_type, ref, pkg_name: Optional[str]
     ) -> List[Package]:
-        clone_url_stripped = clone_url.rstrip(".git")
+        clone_url_stripped = cls._normalize_git_clone_url(clone_url)
 
         packages = (models.Package.query.join(models.Copr)
                     .filter(models.Copr.webhook_secret == webhook_secret)
@@ -184,7 +189,7 @@ def get_for_webhook_rebuild(
         result = []
         for package in packages:
             package_clone_url = package.source_json_dict.get('clone_url', '')
-            package_clone_url_stripped = package_clone_url.rstrip(".git")
+            package_clone_url_stripped = cls._normalize_git_clone_url(package_clone_url)
 
             if package_clone_url_stripped != clone_url_stripped:
                 continue