CTextBox: don't hide if m_nPaintBackground is set to false

Required in CCompmonentsText. Hide of textbox object is unnecessary in
CCompmonentsText objects.

src/gui/widget/textbox.cpp

@@ -640,6 +640,8 @@ void CTextBox::hide (void)
 	if(frameBuffer == NULL)
 		return;
 	
+	if (m_nPaintBackground)
 		frameBuffer->paintBackgroundBoxRel(m_cFrame.iX, m_cFrame.iY, m_cFrame.iWidth, m_cFrame.iHeight);
+	
 	frameBuffer = NULL;
 }