Refs #373 -- Removed outdated comment in RelatedIn lookup.

django/db/models/fields/related_lookups.py

@@ -74,10 +74,6 @@ class RelatedIn(In):
 
     def as_sql(self, compiler, connection):
         if isinstance(self.lhs, ColPairs):
-            # For multicolumn lookups we need to build a multicolumn where clause.
-            # This clause is either a SubqueryConstraint (for values that need
-            # to be compiled to SQL) or an OR-combined list of
-            # (col1 = val1 AND col2 = val2 AND ...) clauses.
             from django.db.models.sql.where import SubqueryConstraint
 
             if self.rhs_is_direct_value():