Use strcmp() instead of strncmp()

strncmp() isn't intended to be a secure strcmp() replacement, it is
designed to be used if you want to compare the first n characters of two
strings. Since we always compare character pointers with string
literals, switch to using strcmp() everywhere.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/recur.c

@@ -943,7 +943,7 @@ recur_repeat_item (void)
       status_mesg (_(outstr), "");
       if (getstring (win[STA].p, user_input, BUFSIZ, 0, 1) == GETSTRING_VALID)
         {
-          if (strlen (user_input) == 1 && strncmp (user_input, "0", 1) == 0)
+          if (strlen (user_input) == 1 && strcmp (user_input, "0") == 0)
             {
               until = 0;
               date_entered = 1;