dont hide anything within__disconnect()

there is no code-path that should lead to warning like:
* uninitialized value used in subroutine
* shutdown on unopened file descriptor
or die in __disconnect().
so just leave it be

lib/Hijk.pm

@@ -137,9 +137,7 @@ sub request {
 }
 
 sub __disconnect {
-    eval {
-        shutdown(delete $SocketCache->{$_[0]}, 2);
-    };
+    shutdown(delete $SocketCache->{$_[0]}, 2);
 }
 
 1;