Fix order of (trim) and (decode) in repl*comps
Before MH had (decode), the format escapes used to be:
%(void{comp})%(trim)%(putstr)
i.e. set the internal str register to the component text, trim
trailing whitespace from it, then print the value. Later (putstr)
was simply replaced by (decode), which first RFC-2047 decodes the
string and then prints it (if it is the outermost function). That
almost always produced the correct result. But this way the
whitespace trimming is done at the wrong point. Correct is to first
decode the string and then trim it. tests/scan/test-mh-format
checks for that.