Invoke TConn().init() in gunicorn worker thread.

MainThread in gunicorn gthread worker calls TConn().init() function,
but when ssl is used that function may raise an ENOTCONN exception.
There is very low probability for that, but still it is needed to catch
potential socket errors during that call, otherwise whole gunicorn worker
with all threads will be crashed.

gunicorn/workers/gthread.py

@@ -46,6 +46,8 @@ def __init__(self, cfg, sock, client, server):
         self.sock.setblocking(False)
 
     def init(self):
+        if self.initialized:
+            return
         self.initialized = True
         self.sock.setblocking(True)
 
@@ -111,7 +113,6 @@ def _wrap_future(self, fs, conn):
         fs.add_done_callback(self.finish_request)
 
     def enqueue_req(self, conn):
-        conn.init()
         # submit the connection to a worker
         fs = self.tpool.submit(self.handle, conn)
         self._wrap_future(fs, conn)
@@ -273,6 +274,7 @@ def handle(self, conn):
         keepalive = False
         req = None
         try:
+            conn.init()
             req = next(conn.parser)
             if not req:
                 return (False, conn)