Remove unused internal function. (#383)

This isn't referenced anywhere internally or externally.

Author: ryanwilson

Firebase/Core/FIRApp.m

@@ -108,24 +108,6 @@ + (void)configureWithOptions:(FIROptions *)options {
   [FIRApp configureDefaultAppWithOptions:options sendingNotifications:YES];
 }
 
-+ (void)configureWithoutSendingNotification {
-  FIROptions *options = [FIROptions defaultOptions];
-  if (!options) {
-    [[NSNotificationCenter defaultCenter]
-        postNotificationName:kFIRAppDiagnosticsNotification
-                      object:nil
-                    userInfo:@{
-                      kFIRAppDiagnosticsConfigurationTypeKey : @(FIRConfigTypeCore),
-                      kFIRAppDiagnosticsErrorKey : [FIRApp errorForMissingOptions]
-                    }];
-    [NSException raise:kFirebaseCoreErrorDomain
-                format:
-                    @"Please check there is a valid "
-                    @"GoogleService-Info.plist in the project."];
-  }
-  [FIRApp configureDefaultAppWithOptions:options sendingNotifications:NO];
-}
-
 + (void)configureDefaultAppWithOptions:(FIROptions *)options
                   sendingNotifications:(BOOL)sendNotifications {
   if (sDefaultApp) {

Firebase/Core/Private/FIRAppInternal.h

@@ -152,12 +152,6 @@ typedef NSString *_Nullable (^FIRAppGetUIDImplementation)(void);
  */
 - (void)getTokenForcingRefresh:(BOOL)forceRefresh withCallback:(FIRTokenCallback)callback;
 
-/**
- * Exposed for use by the Google pod. Configures the default app without sending notifications to
- * other SDKs. Otherwise, behaves exactly like +configure.
- */
-+ (void)configureWithoutSendingNotification;
-
 /**
  * Expose the UID of the current user for Firestore.
  */