add comments about temporary fix with mobile group pubkeys regex

ts/session/types/PubKey.ts

@@ -1,5 +1,8 @@
 export class PubKey {
   public static readonly PUBKEY_LEN = 66;
+  // This is a temporary fix to allow groupPubkeys created from mobile to be handled correctly
+  // They have a different regex to match
+  // FIXME move this to a new class which validates group ids and use it in all places where we have group ids (message sending included)
   public static readonly MOBILE_GROUP_PUBKEY_LEN = 32;
 
   private static readonly regexForMobileGroupID = `__textsecure_group__![0-9a-fA-F]{${PubKey.MOBILE_GROUP_PUBKEY_LEN}}`;

ts/test/session/crypto/MessageEncrypter_test.ts

@@ -52,10 +52,9 @@ describe('MessageEncrypter', () => {
       it('should return a MEDIUM_GROUP_CIPHERTEXT envelope type', async () => {
         const data = crypto.randomBytes(10);
 
-        sandbox.stub(
-          Ratchet,
-          'encryptWithSenderKey'
-        ).resolves({ ciphertext: '' });
+        sandbox
+          .stub(Ratchet, 'encryptWithSenderKey')
+          .resolves({ ciphertext: '' });
 
         const result = await MessageEncrypter.encrypt(
           TestUtils.generateFakePubKey(),