src: remove redundant CHECK

The function `SetAuthTag()` returns early (before reaching this line) if
`!cipher->IsAuthenticatedMode()`, which expands to the exact same
condition that is being `CHECK()`ed here.

Author: tniessen

src/crypto/crypto_cipher.cc

@@ -549,7 +549,6 @@ void CipherBase::SetAuthTag(const FunctionCallbackInfo<Value>& args) {
   } else {
     // At this point, the tag length is already known and must match the
     // length of the given authentication tag.
-    CHECK(Cipher::FromCtx(cipher->ctx_).isSupportedAuthenticatedMode());
     CHECK_NE(cipher->auth_tag_len_, kNoAuthTagLength);
     is_valid = cipher->auth_tag_len_ == tag_len;
   }