fix python version check

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@74358 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/python/temporal/datetime_math.py

@@ -19,7 +19,7 @@ try:
 except:
     has_dateutil = False
 
-if sys.version_info[0]:
+if sys.version_info[0] == 3:
     unicode = str
 
 DAY_IN_SECONDS = 86400

lib/python/temporal/temporal_algebra.py

@@ -470,7 +470,7 @@ from .datetime_math import create_suffix_from_datetime
 from .datetime_math import create_time_suffix
 from .datetime_math import create_numeric_suffix
 
-if sys.version_info[0]:
+if sys.version_info[0] == 3:
     unicode = str
 
 ##############################################################################