utils: disable fcntl in ogClient for Windows

Add conditional import for fcntl as it is only supported for
Linux and causes ogClient for Windows fail to start.

src/utils/net.py

@@ -7,12 +7,15 @@
 # (at your option) any later version.
 
 import array
-import fcntl
+import sys
 import socket
 import struct
 import psutil
 import logging
 
+if sys.platform != "win32":
+    import fcntl
+
 def is_ethernet(interface):
     SIOCGIFHWADDR = 0x8927
     ARPHRD_ETHER = 1