[UserProjectIntegrator] Don't warn about overridden build settings if silent.

lib/cocoapods/installer/user_project_integrator.rb

@@ -6,7 +6,6 @@ require 'active_support/core_ext/array/conversions'
 
 module Pod
   class Installer
-
     class UserProjectIntegrator
       include Pod::Config::Mixin
 
@@ -58,6 +57,8 @@ module Pod
       end
 
       class TargetIntegrator
+        include Pod::Config::Mixin
+
         attr_reader :target_definition
 
         def initialize(target_definition)
@@ -151,6 +152,7 @@ module Pod
               config.base_configuration = xcconfig
             end
 
+            unless config.silent?
               config_build_names_by_overriden_key.each do |key, config_build_names|
                 name = "#{target.attributes["name"]} [#{config_build_names.join(' - ')}]"
                 puts "\n[!] The target `#{name}' overrides the `#{key}' build setting defined in `#{@target_definition.xcconfig_relative_path}'.".yellow
@@ -159,6 +161,7 @@ module Pod
               end
             end
           end
+        end
 
         def add_pods_library
           group = user_project.group("Frameworks") || user_project.main_group