Edit Topic: Validation message about "Replication Factor *" acceptable data
**Describe the bug**
Could be better to have validation message about accepted value for Replication Factor * field

**Set up**
https://www.kafka-ui.provectus.io/


**Steps to Reproduce**
Steps to reproduce the behavior:

1. Navigate to Topics
2. Edit a Topic
3. Change the value of "Replication Factor * " field to be < = 0

**Expected behavior**
Could be better to have information: Value should be > = 1 in a message instead of "400 Bad Request
Fields validation failure" as it works for 

**Screenshots**
<img width="1718" alt="replication factor decrease" src="https://user-images.githubusercontent.com/104780608/177123772-0890654a-cc05-48b2-858e-2f555835a84f.png">



kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml
kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java
index 75c32984617..46ecedd0b3d 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java
@@ -259,6 +259,11 @@ public Mono<ReplicationFactorChangeResponseDTO> changeReplicationFactor(
                 new ValidationException(
                     String.format("Topic already has replicationFactor %s.", actual)));
           }
+          if (requested <= 0) {
+            return Mono.error(
+                new ValidationException(
+                    String.format("Requested replication factor (%s) should be greater or equal to 1.", requested)));
+          }
           if (requested > brokersCount) {
             return Mono.error(
                 new ValidationException(
diff --git a/kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml b/kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml
index 63f313e2ac1..77817f0edb9 100644
--- a/kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml
+++ b/kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml
@@ -592,6 +592,8 @@ paths:
                 $ref: '#/components/schemas/ReplicationFactorChangeResponse'
         404:
           description: Not found
+        400:
+          description: Bad Request
 
   /api/clusters/{clusterName}/topics/{topicName}/messages:
     get:
@@ -3052,7 +3054,6 @@ components:
       properties:
         totalReplicationFactor:
           type: integer
-          minimum: 1
       required:
         - totalReplicationFactor
 
