Reverse asyncio/trio check per review feedback

Author: pquentin

elastic_transport/_async_transport.py

@@ -381,9 +381,9 @@ async def perform_request(  # type: ignore[override, return]
                     )
 
     async def sniff(self, is_initial_sniff: bool = False) -> None:  # type: ignore[override]
-        if sniffio.current_async_library() != "asyncio":
+        if sniffio.current_async_library() == "trio":
             raise ValueError(
-                f"Asynchronous sniffing only works with the 'asyncio' library, got {sniffio.current_async_library}"
+                f"Asynchronous sniffing is not supported with the 'trio' library, got {sniffio.current_async_library}"
             )
         await self._async_call()
         task = self._create_sniffing_task(is_initial_sniff)
@@ -477,7 +477,7 @@ async def _async_call(self) -> None:
             return  # Call at most once!
 
         self._async_library = sniffio.current_async_library()
-        if self._async_library != "asyncio":
+        if self._async_library == "trio":
             return
 
         self._loop = asyncio.get_running_loop()