do not kill listener threads on error

server/src/events.rs

@@ -88,7 +88,7 @@ impl Events {
                 },
 
                 Err(e) => {
-                    return Err(format_err!("events error err={:?}", e));
+                    warn!("events error err={:?}", e);
                 },
             };
         }

server/src/warden.rs

@@ -57,7 +57,7 @@ impl Warden {
                 },
 
                 Err(e) => {
-                    return Err(format_err!("err={:?}", e));
+                    warn!("err={:?}", e);
                 },
             };
         }