civetweb.c: fix sscanf format string to %u
civetweb.c: fix sscanf format string to %u

[src/civetweb.c:5728]: (warning) %d in format string (no. 2) requires
 'int *' but the argument type is 'unsigned int *'.

Signed-off-by: Danny Al-Gaaf <473e39ac77cf392f0dd9bacde8409de76c14d006@bisect.de>

GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver