.gitignore: remove *.xcodeproj

I'm about to add one to the tree.

Change-Id: Iad25d8965d1095349588e11a5050f986e5ad2e76
Reviewed-on: https://go-review.googlesource.com/14260
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>

Author: crawshaw

.gitignore

@@ -4,7 +4,6 @@ last-change
 *.app
 *.framework
 *.aar
-*.xcodeproj
 *.iml
 .idea
 .gradle
@@ -14,4 +13,4 @@ example/bind/android/local.properties
 example/bind/android/gradlew*
 example/bind/android/gradle
 example/bind/android/build
-example/bind/android/app/build
+example/bind/android/app/build