Http: Set a sane default connection timeout

src/slic3r/Utils/Http.hpp

@@ -55,6 +55,8 @@ public:
 	Http& operator=(const Http &) = delete;
 	Http& operator=(Http &&) = delete;
 
+	// Sets a maximum connection timeout in seconds
+	Http& timeout(long timeout);
 	// Sets a maximum size of the data that can be received.
 	// A value of zero sets the default limit, which is is 5MB.
 	Http& size_limit(size_t sizeLimit);