t.vect.export: fixed wrong parameter name

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@63285 15284696-431f-4ddb-bdfa-cd5b030d7da7

temporal/t.vect.export/t.vect.export.py

@@ -69,7 +69,7 @@ def main():
     _input = options["input"]
     output = options["output"]
     compression = options["compression"]
-    workdir = options["workdir"]
+    workdir = options["directory"]
     where = options["where"]
     _format = options["format"]