mention brokenness

docs/curl-config.1

@@ -64,7 +64,7 @@ Outputs version information about the installed libcurl, in numerical mode.
 This outputs the version number, in hexadecimal, with 8 bits for each part;
 major, minor, patch. So that libcurl 7.7.4 would appear as 070704 and libcurl
 12.13.14 would appear as 0c0d0e... Note that the initial zero might be
-omitted.
+omitted. (This option was broken in the 7.15.0 release.)
 .SH "EXAMPLES"
 What linker options do I need when I link with libcurl?