qjson: Drop trailing space for pretty formatting

qjson: Drop trailing space for pretty formatting

For the pretty formatting, the functions converting QDicts and QLists to
JSON should not print a space after the comma separating objects,
because a newline will emitted immediately afterwards, making the
whitespace superfluous.

Signed-off-by: Max Reitz <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>