Fixed bug regarding prescript being called if None

ssh-host.py

@@ -1,4 +1,3 @@
-#!/usr/bin/python
 import subprocess
 import argparse
 import configparser
@@ -14,11 +13,12 @@ if __name__ == "__main__":
     parser.add_argument('arg',nargs = '*')
     args = parser.parse_args()
 
-    pre = '~/.ssh/config/{}'.format(args.pre_script)
+    if pre:
+        pre = '~/.ssh/config/{}'.format(args.pre_script)
+        subprocess.check_call(pre)
     if args.wan:
         host = cp['wan'][args.name]
     elif args.lan:
         host = cp['lan'][args.name]
     cmd = ['ssh','-F','~/.ssh/{}.cfg'.format(args.name),host] + args.arg
-    subprocess.check_call(pre)
     subprocess.call(cmd)