os/reporter.h: Don't enable if connection fails

If opening a report session fails (for example because of invalid
session arguments) and an exception is thrown during the session
construction, the report would wrongly keep the enabled state.
By moving the assignment of the state after the construction,
the report stays disabled as it should be.

os/include/os/reporter.h

@@ -52,12 +52,12 @@ class Genode::Reporter : Noncopyable
 		{
 			if (enabled == _enabled) return;
 
-			_enabled = enabled;
-
-			if (_enabled)
+			if (enabled)
 				_conn.construct(_name.string());
 			else
 				_conn.destruct();
+
+			_enabled = enabled;
 		}
 
 		bool is_enabled() const { return _enabled; }