Add error message when running trytond_import_zip without proteus

issue6266
review32031002

scripts/trytond_import_zip

@@ -1,19 +1,25 @@
 #!/usr/bin/env python
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
+import csv
+import os
+import sys
 import urllib2
 import zipfile
-import csv
-import sys
-from io import BytesIO
+
 from argparse import ArgumentParser
+from io import BytesIO
 
 try:
     from progressbar import ProgressBar, Bar, ETA, SimpleProgress
 except ImportError:
     ProgressBar = None
 
-from proteus import Model, config
+try:
+    from proteus import Model, config
+except ImportError:
+    prog = os.path.basename(sys.argv[0])
+    sys.exit("proteus must be installed to use %s" % prog)
 
 
 def clean(code):