Delete 'intr' from NFS mount options

We still recommend to use 'intr' option here [1], but seems that 'intr' is a deprecated mount option for RHEL 6 and 7, according to this KCS [2]

[1] https://access.redhat.com/documentation/en-us/red_hat_amq/2020.q4/html-single/configuring_amq_broker/index#assembly_br-configuring-shared-store-high-availability-configuring
[2] https://access.redhat.com/solutions/157873