Fix duplicate branch in Spree::Preferences::Preferable private method

:string, :text and :password cases have the same value

.rubocop_todo.yml

@@ -23,16 +23,6 @@ Lint/ConstantDefinitionInBlock:
     - 'spec/validators/date_time_string_validator_spec.rb'
     - 'spec/validators/integer_array_validator_spec.rb'
 
-# Offense count: 6
-# Configuration parameters: IgnoreLiteralBranches, IgnoreConstantBranches.
-Lint/DuplicateBranch:
-  Exclude:
-    # - 'app/helpers/spree/admin/base_helper.rb'
-    # - 'app/models/enterprise.rb'
-    # - 'app/models/spree/calculator.rb'
-    # - 'app/models/spree/preference.rb'
-    - 'app/models/spree/preferences/preferable.rb'
-
 # Offense count: 2
 Lint/DuplicateMethods:
   Exclude:

app/models/spree/preferences/preferable.rb

@@ -111,9 +111,7 @@ module Spree
 
       def convert_preference_value(value, type)
         case type
-        when :string, :text
-          value.to_s
-        when :password
+        when :string, :text, :password
           value.to_s
         when :decimal
           value = 0 if value.blank?