CORD-1734 Reduce number of worker threads

Change-Id: Iba1a1e11ba87fb452c90ef6d8b9f3ee335bd3960
diff --git a/xos/coreapi/grpc_server.py b/xos/coreapi/grpc_server.py
index 69a50fc..8edf87f 100644
--- a/xos/coreapi/grpc_server.py
+++ b/xos/coreapi/grpc_server.py
@@ -121,7 +121,7 @@
     def __init__(self, port=50055):
         self.port = port
         log.info('Initializing GRPC Server', port = port)
-        self.thread_pool = futures.ThreadPoolExecutor(max_workers=10)
+        self.thread_pool = futures.ThreadPoolExecutor(max_workers=1)
         self.server = grpc.server(self.thread_pool)
 
         server_key = open(SERVER_KEY,"r").read()