Fixed a mislabeled error message

Author: hiranya911

FirebaseAdmin/FirebaseAdmin.Tests/Auth/UserRecordTest.cs

@@ -144,4 +144,4 @@ public void AllProperties()
             Assert.Equal(UserRecord.UnixEpoch.AddMilliseconds(150), metadata.LastSignInTimestamp);
         }
     }
-}
+}

FirebaseAdmin/FirebaseAdmin/Auth/FirebaseUserManager.cs

@@ -106,7 +106,7 @@ public async Task UpdateUserAsync(
                 "accounts:update", payload, cancellationToken).ConfigureAwait(false);
             if (payload.Uid != (string)response["localId"])
             {
-                throw new FirebaseException($"Failed to get user: {payload.Uid}");
+                throw new FirebaseException($"Failed to update user: {payload.Uid}");
             }
         }
 

FirebaseAdmin/FirebaseAdmin/Auth/UserArgs.cs

@@ -104,4 +104,4 @@ internal UpdateUserRequest(UserArgs args)
             public string CustomClaims { get; set; }
         }
     }
-}
+}