client: make GetEventLoop() public

src/event/BufferedSocket.hxx

@@ -42,6 +42,7 @@ public:
 		ScheduleRead();
 	}
 
+	using SocketMonitor::GetEventLoop;
 	using SocketMonitor::IsDefined;
 	using SocketMonitor::Close;
 

src/event/FullyBufferedSocket.hxx

@@ -37,6 +37,7 @@ public:
 		 output(normal_size, peak_size) {
 	}
 
+	using BufferedSocket::GetEventLoop;
 	using BufferedSocket::IsDefined;
 
 	void Close() noexcept {