fix error message

Author: KirillKurdyukov

src/Ydb.Sdk/test/Ydb.Sdk.Topic.Tests/ReaderUnitTests.cs

@@ -375,9 +375,9 @@ public async Task Initialize_WhenInitResponseStatusIsNotRetryable_ShouldThrowRea
             SubscribeSettings = { new SubscribeSettings("/topic") }
         }.Build();
 
-        Assert.Equal("Initialization failed: Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
+        Assert.Equal("Initialization failed! Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
             (await Assert.ThrowsAsync<ReaderException>(async () => await reader.ReadAsync())).Message);
-        Assert.Equal("Initialization failed: Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
+        Assert.Equal("Initialization failed! Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
             (await Assert.ThrowsAsync<ReaderException>(async () => await reader.ReadBatchAsync())).Message);
 
         _mockStream.Verify(stream => stream.Write(It.Is<FromClient>(msg =>

src/Ydb.Sdk/test/Ydb.Sdk.Topic.Tests/WriterIntegrationTests.cs

@@ -39,7 +39,7 @@ public async Task WriteAsync_WhenTopicNotFound_ReturnNotFoundException()
             { ProducerId = "producerId" }.Build();
 
         Assert.Contains(
-            $"Initialization failed: Status: SchemeError, Issues:\n[500017] Error: no path 'local/{_topicName + "_not_found"}'",
+            $"Initialization failed! Status: SchemeError, Issues:\n[500017] Error: no path 'local/{_topicName + "_not_found"}'",
             (await Assert.ThrowsAsync<WriterException>(() => writer.WriteAsync("hello world"))).Message
         );
     }

src/Ydb.Sdk/test/Ydb.Sdk.Topic.Tests/WriterUnitTests.cs

@@ -295,9 +295,9 @@ public async Task
         await using var writer = new WriterBuilder<long>(_mockIDriver.Object, "/topic-6")
             { ProducerId = "producerId" }.Build();
 
-        Assert.Equal("Initialization failed: Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
+        Assert.Equal("Initialization failed! Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
             (await Assert.ThrowsAsync<WriterException>(() => writer.WriteAsync(123L))).Message);
-        Assert.Equal("Initialization failed: Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
+        Assert.Equal("Initialization failed! Status: SchemeError, Issues:\n[0] Fatal: Topic not found\n",
             (await Assert.ThrowsAsync<WriterException>(() => writer.WriteAsync(1L))).Message);
 
         // check not attempt repeated!!!