better guess of instance in etext request

[eroux]

For scan requests going from the image instance to the instance is just adding an M at the beginning, but for etext request it should be removing IE and prefixing with MW. The issue is visible on https://editor.bdrc.io/etextrequest when filling etextinstance but not reproduction of and looking at the http query

[berger-n]

fixed: https://editor.bdrc.io/

[eroux]

thanks!