Avoid deprecation warnings.

Author: wvengen

lib/ice_cube/parsers/ical_parser.rb

@@ -36,7 +36,7 @@ def self.rule_from_ical(ical)
         when 'COUNT'
           params[:count] = value.to_i
         when 'UNTIL'
-          params[:until] = DateTime.parse(value).to_time.utc
+          params[:until] = Time.parse(value).utc
         when 'WKST'
           params[:wkst] = TimeUtil.ical_day_to_symbol(value)
         when 'BYSECOND'