Remove outdated comments [ci skip]

These comments were added at dd257a3c
but outdated since #2086.

activerecord/test/cases/multiparameter_attributes_test.rb

@@ -18,8 +18,6 @@ def test_multiparameter_attributes_on_date_with_empty_year
     attributes = { "last_read(1i)" => "", "last_read(2i)" => "6", "last_read(3i)" => "24" }
     topic = Topic.find(1)
     topic.attributes = attributes
-    # note that extra #to_date call allows test to pass for Oracle, which
-    # treats dates/times the same
     assert_nil topic.last_read
   end
 
@@ -27,8 +25,6 @@ def test_multiparameter_attributes_on_date_with_empty_month
     attributes = { "last_read(1i)" => "2004", "last_read(2i)" => "", "last_read(3i)" => "24" }
     topic = Topic.find(1)
     topic.attributes = attributes
-    # note that extra #to_date call allows test to pass for Oracle, which
-    # treats dates/times the same
     assert_nil topic.last_read
   end
 
@@ -36,8 +32,6 @@ def test_multiparameter_attributes_on_date_with_empty_day
     attributes = { "last_read(1i)" => "2004", "last_read(2i)" => "6", "last_read(3i)" => "" }
     topic = Topic.find(1)
     topic.attributes = attributes
-    # note that extra #to_date call allows test to pass for Oracle, which
-    # treats dates/times the same
     assert_nil topic.last_read
   end
 
@@ -45,8 +39,6 @@ def test_multiparameter_attributes_on_date_with_empty_day_and_year
     attributes = { "last_read(1i)" => "", "last_read(2i)" => "6", "last_read(3i)" => "" }
     topic = Topic.find(1)
     topic.attributes = attributes
-    # note that extra #to_date call allows test to pass for Oracle, which
-    # treats dates/times the same
     assert_nil topic.last_read
   end
 
@@ -54,8 +46,6 @@ def test_multiparameter_attributes_on_date_with_empty_day_and_month
     attributes = { "last_read(1i)" => "2004", "last_read(2i)" => "", "last_read(3i)" => "" }
     topic = Topic.find(1)
     topic.attributes = attributes
-    # note that extra #to_date call allows test to pass for Oracle, which
-    # treats dates/times the same
     assert_nil topic.last_read
   end
 
@@ -63,8 +53,6 @@ def test_multiparameter_attributes_on_date_with_empty_year_and_month
     attributes = { "last_read(1i)" => "", "last_read(2i)" => "", "last_read(3i)" => "24" }
     topic = Topic.find(1)
     topic.attributes = attributes
-    # note that extra #to_date call allows test to pass for Oracle, which
-    # treats dates/times the same
     assert_nil topic.last_read
   end