Removed useless check if self::$trustProxies is set

In Request::getClientIps() on line 772 there is a check if self::$trustedProxies is not set. If this condition evaluates to true the method will return.
Because of this the second identical check on line 783 will never evaluate to true, as when reaching this position self::$trustedProxies must be set.
Merge branch '2.3'

* 2.3: (24 commits)
  Add german translation for several validators (Greater/Equal/Less)
  No Entity Manager defined exception
  fixed CS
  [Acl] Fix for issue #9433
  [Validator] fix docblock typos
  [DependencyInjection] removed the unused Reference and Parameter classes use statements from the compiled container class
  Removed useless check if self::$trustProxies is set
  Fix mistake in translation's service definition.
  if handler_id is identical to null fix
  CS fix
  Fixed ModelChoiceList tests in Propel1 bridge.
  [AclProvider] Fix incorrect behaviour when partial results returned from cache
  Check if the pipe array is empty before calling stream_select()
  [Intl] fixed datetime test as described in #9455
  bumped Symfony version to 2.3.8
  updated VERSION for 2.3.7
  updated CHANGELOG for 2.3.7
  re-factor Propel1 ModelChoiceList
  [Form] Added method Form::getClickedButton() to remove memory leak in FormValidator
  [Locale] fixed the failing test described in #9455
  ...

Conflicts:
	src/Symfony/Bridge/Propel1/Form/ChoiceList/ModelChoiceList.php
	src/Symfony/Bridge/Propel1/Tests/Fixtures/ItemQuery.php
	src/Symfony/Bridge/Propel1/Tests/Form/ChoiceList/ModelChoiceListTest.php
	src/Symfony/Bridge/Propel1/Tests/Propel1TestCase.php
	src/Symfony/Component/Form/Tests/CompoundFormTest.php
	src/Symfony/Component/HttpKernel/Kernel.php
	src/Symfony/Component/Process/Process.php