BUG in function setValue for number object

[1simone0]

Actually is not possible to update a negative number even if in the Nextion editor numbers accept negative values. It's just enough to modify the function bool setValue(uint32_t number); with bool setValue(int32_t number); and use the function itoa instead utoa inside that.

[s-celles]

Maybe one day @itead @shennongmin @zhangabc @hxming123456 @huangxianming will consider contributions such as #85
... or not 😄