Tweak proxy client

app/main.py

@@ -1179,16 +1179,14 @@ async def nodeinfo(
     )
 
 
-proxy_client = httpx.AsyncClient(
-    follow_redirects=True,
-    timeout=httpx.Timeout(timeout=10.0),
-    transport=httpx.AsyncHTTPTransport(retries=1),
-)
-
-
 async def _proxy_get(
     request: starlette.requests.Request, url: str, stream: bool
 ) -> httpx.Response:
+    async with httpx.AsyncClient(
+        follow_redirects=True,
+        timeout=httpx.Timeout(timeout=10.0),
+        transport=httpx.AsyncHTTPTransport(retries=1),
+    ) as proxy_client:
         # Request the URL (and filter request headers)
         proxy_req = proxy_client.build_request(
             request.method,