Release 6.20.1: Introduced property to specify a whitelist for client identifiers

[changerequest]

Introduced property com.openexchange.IPCheckWhitelist to specify a comma-separated list of client identifiers for that no IP check will be performed. By default that property is disabled.
See US6770.

# Specify a comma-separated list of client patterns that do bypass IP check
# E.g. com.openexchange.IPCheckWhitelist=Mobile