Fix compilation for FreeBSD

libyang-source/src/plugins_types/date_and_time.c:122:19: warning: arithmetic on a pointer to the function type 'char *(int, int)' is a GNU extension [-Wpointer-arith]
 	        val->time += timezone;
 	                  ^  ~~~~~~~~
libyang-source/src/plugins_types/date_and_time.c:122:19: warning: incompatible pointer to integer conversion assigning to 'time_t' (aka 'long') from 'char *(*)(int, int)' [-Wint-conversion]
 	        val->time += timezone;
 	                  ^  ~~~~~~~~
 	/usr/home/ci/cibuild.167/libyang-source/src/plugins_types/date_and_time.c:125:13: error: use of undeclared identifier 'daylight'
 	        if (daylight) {
 	            ^
2 warnings and 1 error generated.

* localtime_r() tells about DST already. In FreeBSD `daylight` variable
is not exposed. I believe we can use DST from tm?

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
diff --git a/compat/strptime.c b/compat/strptime.c
index 38e9d03..0520a75 100644
--- a/compat/strptime.c
+++ b/compat/strptime.c
@@ -166,7 +166,7 @@
             for (i = 1; i <= min + range && isdigit(*s); i *= 10) {
                 *dest = *dest * 10 + *s++ - '0';
             }
-            if (*dest - min >= (unsigned)range) {
+            if (*dest - min >= range) {
                 return 0;
             }
             *dest -= adj;