CA-37466: retry xapi login to handle transient errors
CA-37466: retry xapi login to handle transient errors

Signed-off-by: Simon Rowe <6b0999b796d5e18833f96f31b20ec46c7a765474@eu.citrix.com>

johnelse/xcp-rrdd,koushikcgit/xcp-rrdd,koushikcgit/xcp-networkd,djs55/xcp-rrdd,johnelse/xcp-rrdd,sharady/xcp-networkd,djs55/squeezed,simonjbeaumont/xcp-rrdd,robhoes/squeezed,djs55/xcp-networkd,koushikcgit/xcp-networkd,koushikcgit/xcp-rrdd,simonjbeaumont/xcp-rrdd,djs55/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd