Remove unnecessary monkey patching

Author: pabloh

lib/rake/ext/time.rb

@@ -4,13 +4,15 @@
 require 'rake/early_time'
 require 'rake/late_time'
 
-class Time # :nodoc: all
-  alias rake_original_time_compare :<=>
-  def <=>(other)
-    if Rake::EarlyTime === other || Rake::LateTime === other
-      - other.<=>(self)
-    else
-      rake_original_time_compare(other)
+if RUBY_VERSION < "1.9"
+  class Time # :nodoc: all
+    alias rake_original_time_compare :<=>
+    def <=>(other)
+      if Rake::EarlyTime === other || Rake::LateTime === other
+        - other.<=>(self)
+      else
+        rake_original_time_compare(other)
+      end
     end
   end
 end