Merge pull request #2597 from ales-erjavec/disable-pyqtgraph-exit-handlers

[FIX] Disable pyqtgraph's exit cleanup handler

Author: kernc

Orange/canvas/__main__.py

@@ -46,6 +46,10 @@
 import signal
 signal.signal(signal.SIGINT, signal.SIG_DFL)
 
+# Disable pyqtgraph's atexit and QApplication.aboutToQuit cleanup handlers.
+import pyqtgraph
+pyqtgraph.setConfigOption("exitCleanup", False)
+
 
 def fix_osx_10_9_private_font():
     # Fix fonts on Os X (QTBUG 47206, 40833, 32789)