normalize shebang for utils, example script (#1679)

sabnzbd/utils/checkdir.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 
 """
 Functions to check if the path filesystem uses FAT

sabnzbd/utils/diskspeed.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 
 import time
 import os

sabnzbd/utils/internetspeed.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/usr/bin/python3
 
 """
 Module to measure and report Internet speed

sabnzbd/utils/systrayiconthread.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 # based on SysTrayIcon.py by Simon Brunning - simon@brunningonline.net
 # http://www.brunningonline.net/simon/blog/archives/001835.html
 # http://www.brunningonline.net/simon/blog/archives/SysTrayIcon.py.html

scripts/Sample-PostProc.py

@@ -1,10 +1,10 @@
-#!/usr/bin/env python
+#!/usr/bin/python3
 # Example Post-Processing Script for SABnzbd (3.0.0 and higher), written in Python.
 # For Linux, MacOS, Windows and any other platform with Python
 # See https://sabnzbd.org/wiki/scripts/post-processing-scripts for details
 #
 # Example test run on Linux:
-# env SAB_VERSION=X.Y SAB_AVG_BPS=666 python ./Sample-PostProc.py somedir222 nzbname CleanJobName123 Index12 Cat88 MyGroup PP0 https://example.com/
+# env SAB_VERSION=X.Y SAB_AVG_BPS=666 python3 ./Sample-PostProc.py somedir222 nzbname CleanJobName123 Index12 Cat88 MyGroup PP0 https://example.com/
 
 import sys, os