Fix a minor typo. (#1032) (#1037)

(cherry picked from commit dd9a0a14c89d57e43898d4b866b8c161e4ff8506)
diff --git a/Doc/library/asyncio-protocol.rst b/Doc/library/asyncio-protocol.rst
index 482ffbb..3f55506 100644
--- a/Doc/library/asyncio-protocol.rst
+++ b/Doc/library/asyncio-protocol.rst
@@ -384,7 +384,7 @@
 
 .. method:: Protocol.eof_received()
 
-   Calls when the other end signals it won't send any more data
+   Called when the other end signals it won't send any more data
    (for example by calling :meth:`write_eof`, if the other end also uses
    asyncio).