Update plugins/communication_protocols/http/src/utcp_http/http_communication_protocol.py

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

Author: h3xxit

plugins/communication_protocols/http/src/utcp_http/http_communication_protocol.py

@@ -311,7 +311,7 @@ async def call_tool(self, caller, tool_name: str, tool_args: Dict[str, Any], too
                 ) as response:
                     response.raise_for_status()
 
-                    content_type = response.headers.get('Content-Type', '')
+                    content_type = response.headers.get('Content-Type', '').lower()
                     if 'application/json' in content_type:
                         return await response.json()
                     return await response.text()