Help: Change URL sanitization to be safer

src/Mod/Help/Help.py

@@ -169,7 +169,7 @@ def location_url(url_localized: str, url_english: str) -> tuple:
         req = urllib.request.Request(url_localized)
         with urllib.request.urlopen(req) as response:
             html = response.read().decode("utf-8")
-            if re.search(MD_RAW_URL, url_localized):
+            if url_localized.startswith(MD_RAW_URL):
                 pagename_match = re.search(r"Name/.*?:\s*(.+)", html)
             else:
                 # Pages from FreeCAD Wiki fall here