Only show the display screen on startup if it is not on the primary screen.

bzr-revno: 1000

openlp/core/ui/maindisplay.py

@@ -155,9 +155,9 @@ class MainDisplay(DisplayWidget):
             self.webView.setHtml(build_html(serviceItem, self.screen,
                 self.parent.alertTab, self.isLive))
             self.initialFrame = True
-            self.show()
             # To display or not to display?
             if not self.screen[u'primary']:
+                self.show()
                 self.primary = False
             else:
                 self.primary = True