#244 RC2: PENDING OFF doesn't work for backslash

[LesK]

With RC2, 'COMMAND :'pline 'SET PENDING OFF' in a macro
doesn't clear a backslash in the prefix area, although PENDING.0=0 after the code runs.

RESET ALL does clear it, or it can be manually deleted.

3.3b3 does not exhibit this behavior.