Chat console: Prevent input loss on double open

src/gui/guiChatConsole.cpp

@@ -106,9 +106,13 @@ GUIChatConsole::~GUIChatConsole()
 
 void GUIChatConsole::openConsole(f32 scale)
 {
+	if (m_open)
+		return;
+
 	assert(scale > 0.0f && scale <= 1.0f);
 
 	m_open = true;
+
 	m_desired_height_fraction = scale;
 	m_desired_height = scale * m_screensize.Y;
 	reformatConsole();