[Dxspider-support] Issue with sh/dx by_zone

[Martin Davies G0HDB]

GB7DXC-5 is running v1.57 build 524 on a Raspberry Pi 3.

When either I, as sysop from the console, or a user enters the command 'sh/dx t30un 
by_zone 14,15' the returned listing doesn't show T30UN but a variety of other stations that 
appear to have been spotted by users in zones 14 and 15.  However, if I do 'sh/dx t30un 
by_zone 14' the list only shows spots of T30UN originated in zone 14, as expected.

I've tried several variations on 'by_zone 14,15' but none seem to return the expected listing of 
spots of only T30UN.  The error also occurs when any other callsign, eg. E51CIK, is included 
in the command.

What's the correct syntax for getting a list of spots originated in multiple zones, or is there a 
tiny weeny bug in the s/ware??!!

--
73, Martin G0HDB