Bad cluster configs shouldn't brick the cluster screen

[THEjoezack]

Sample of a bad config that takes down the cluster page indefinitely:

group.id=grafka
bootstrap.servers=localhost:1234

schema.registry.url=http://localhost:8081

key.serializer=org.apache.kafka.common.serialization.StringSerializer
value.serializer=io.confluent.kafka.serializers.KafkaAvroSerializer

key.deserializer=org.apache.kafka.common.serialization.StringDeserializer
value.deserializer=io.confluent.kafka.serializers.KafkaAvroDeserializer

avro.specific.reader=true

[THEjoezack]

Maybe it should validate the settings before saving? (In addition to not breaking everything)