title: undefined symbols for architecture armv7s
body: <p>When i build my old version app ios 4.3 i have this warning </p>
  
  <pre><code>Undefined symbols for architecture armv7s:
    "_OBJC_CLASS_$_SSSwitch", referenced from:
        objc-class-ref in LoginViewController.o
    "_OBJC_CLASS_$_SSHUDView", referenced from:
        objc-class-ref in ContractorInfoViewController.o
        objc-class-ref in ContractorListViewController.o
        objc-class-ref in EvenementBilleterieViewController.o
        objc-class-ref in EvenementCoupDeCoeurViewController.o
        objc-class-ref in EvenementRequestViewController.o
        objc-class-ref in GourmetCoupDeCoeurViewController.o
        objc-class-ref in GourmetRequestViewController.o
        ...
  ld: symbol(s) not found for architecture armv7s
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>please help me</p>