Switch import logic between windows and the other OS

As explained here
dateutil/dateutil#11

"""
... consumers (e.g. pandas) is supposed to be using dateutil.tz.gettz()
instead of dateutil.zoneinfo.gettz()...
"""

Signed-off-by: Justin Lecher <jlec@gentoo.org>

Author: jlec

pandas/tslib.pyx

@@ -43,9 +43,9 @@ from dateutil.tz import (tzoffset, tzlocal as _dateutil_tzlocal, tzfile as _date
                          tzutc as _dateutil_tzutc)
 from pandas.compat import is_platform_windows
 if is_platform_windows():
-    from dateutil.tz import gettz as _dateutil_gettz
-else:
     from dateutil.zoneinfo import gettz as _dateutil_gettz
+else:
+    from dateutil.tz import gettz as _dateutil_gettz
 
 from pytz.tzinfo import BaseTzInfo as _pytz_BaseTzInfo
 from pandas.compat import parse_date, string_types, PY3, iteritems