Fix case sensitivity of AppRTCDemo include dirs

BUG=4341
R=tkchin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/40939004

Patch from Vicken Simonian <vsimon@gmail.com>.

Cr-Commit-Position: refs/heads/master@{#8521}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8521 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/libjingle_examples.gyp b/talk/libjingle_examples.gyp
index 374bffb..6b8fe19 100755
--- a/talk/libjingle_examples.gyp
+++ b/talk/libjingle_examples.gyp
@@ -187,11 +187,11 @@
             'examples/objc/AppRTCDemo/RTCSessionDescription+JSON.m',
           ],
           'include_dirs': [
-            'examples/objc/APPRTCDemo',
+            'examples/objc/AppRTCDemo',
           ],
           'direct_dependent_settings': {
             'include_dirs': [
-              'examples/objc/APPRTCDemo',
+              'examples/objc/AppRTCDemo',
             ],
           },
           'export_dependent_settings': [