client: un-inline the destructor

src/client/Client.cxx

@@ -25,6 +25,12 @@
 
 const Domain client_domain("client");
 
+Client::~Client() noexcept
+{
+	if (FullyBufferedSocket::IsDefined())
+		FullyBufferedSocket::Close();
+}
+
 Instance &
 Client::GetInstance() noexcept
 {

src/client/Client.hxx

@@ -101,10 +101,7 @@ public:
 	       unsigned _permission,
 	       int num) noexcept;
 
-	~Client() noexcept {
-		if (FullyBufferedSocket::IsDefined())
-			FullyBufferedSocket::Close();
-	}
+	~Client() noexcept;
 
 	using FullyBufferedSocket::GetEventLoop;