CURLINFO_REDIRECT_URL.3: mention the CURLOPT_MAXREDIRS case

... supported since 7.54.1

docs/libcurl/opts/CURLINFO_REDIRECT_URL.3

@@ -33,6 +33,9 @@ take you to if you would enable \fICURLOPT_FOLLOWLOCATION(3)\fP. This can come
 very handy if you think using the built-in libcurl redirect logic isn't good
 enough for you but you would still prefer to avoid implementing all the magic
 of figuring out the new URL.
+
+This URL is also set if the \fICURLOPT_MAXREDIRS(3)\fP limit prevented a
+redirect to happen (since 7.54.1).
 .SH PROTOCOLS
 HTTP(S)
 .SH EXAMPLE