spell: fix refresh of bar item "spell_suggest" when the input becomes empty (closes #1586)

When the input is empty, length of string is zero: when sending zero to
function weechat_string_dyn_alloc, the function returns NULL and therefore we
return immediately instead of handling the empty input, which is a valid value.

The regression was introduced by the use of dynamic strings, commit:
299f74bfef9e0d239ad141a4df3b2dcf11a4c0da

0 files changed, 0 insertions, 0 deletions