sd-resolv: remove left-over comment

We are anyway breaking the API by renaming everything, so that is not a concern.

src/libsystemd/sd-resolv.c

@@ -1111,11 +1111,6 @@ void sd_resolv_freeanswer(unsigned char *answer) {
         if (!answer)
                 return;
 
-        /* Please note that this function is new in libresolv 0.4. In
-         * older versions you were supposed to free the answer directly
-         * with free(). Hence, if this function is changed to do more than
-         * just a simple free() this must be considered ABI/API breakage! */
-
         free(answer);
 
         errno = saved_errno;