Improve wording in topic create: replication factor must be odd

[daisukebe]

Redpanda console fails to create a topic when I specify an even number for replication factor with the following message but this isn't accurate.

Failed to create topic, kafka responded with the following error: INVALID_REPLICATION_FACTOR: Replication factor is below 1 or larger than the number of available brokers.

Let's make the wording better as rpk does per https://github.com/redpanda-data/redpanda/commit/2eeed7658e493ebc08d19941bea17983b36080c4

[vj-codes]

@weeco hey I would like to work on this!

[weeco]

Hey @vj-codes - sounds good, I assigned you :).

[twmb]

ping @vj-codes

[rikimaru0345]

fixed in https://github.com/redpanda-data/console/pull/1166