Free the branch iterator

Author: yori

ObjectiveGit/GTRepository.m

@@ -407,6 +407,10 @@ - (BOOL)enumerateBranchesWithType:(GTBranchType)type error:(NSError **)error usi
 		if (error) *error = [NSError git_errorFor:gitError description:@"Branch enumeration failed"];
 		return NO;
 	}
+	
+	@onExit {
+		git_branch_iterator_free(iter);
+	};
 
 	git_branch_t branchType;
 	while ((gitError = git_branch_next(&gitRef, &branchType, iter)) == GIT_OK) {