Repaired feature to save images from video downlink (fixes #1239)

problem:
in src/ui$/HUD.cc copyImage(UASInterface* u): u->getImage() was called twice. The first called already erased the buffer.

changes:
src/ui/HUD.cc: copyImage(UASInterface* u): instead of getting the image a second time, we take the one we already fetched

src/ui/HUD.cc

@@ -1363,14 +1363,14 @@ void HUD::copyImage(UASInterface* uas)
         QImage temp_im = u->getImage();
         if (temp_im.byteCount() > 0) {
             this->glImage = temp_im;
-        }
 
-        // Save to directory if logging is enabled
-        if (imageLoggingEnabled)
-        {
-            u->getImage().save(QString("%1/%2.png").arg(imageLogDirectory).arg(imageLogCounter));
-            imageLogCounter++;
-        }
+			// Save to directory if logging is enabled
+			if (imageLoggingEnabled)
+			{
+				temp_im.save(QString("%1/%2.png").arg(imageLogDirectory).arg(imageLogCounter));
+				imageLogCounter++;
+			}
+		}
     }
 }