fix typo in NO_SERVER case

Reported-by: shyswork via github
Signed-off-by: Andy Green <andy.green@linaro.org>
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index b759b39..b0f25fe 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -1539,7 +1539,7 @@
 
 #ifdef LWS_NO_SERVER
 int
-_libwebsocket_rx_flow_control(struct libswebsocket *wsi)
+_libwebsocket_rx_flow_control(struct libwebsocket *wsi)
 {
 	return 0;
 }