valgrind: update to 3.15.0

[casouri (Yuan Fu)]

I'm on Catalina, and installing valgrind gives the following error:

$ sudo port install valgrind
--->  Computing dependencies for valgrind
--->  Fetching archive for valgrind
--->  Attempting to fetch valgrind-3.14.0_0.darwin_19.x86_64.tbz2 from https://packages.macports.org/valgrind
--->  Attempting to fetch valgrind-3.14.0_0.darwin_19.x86_64.tbz2 from http://ywg.ca.packages.macports.org/mirror/macports/packages/valgrind
--->  Attempting to fetch valgrind-3.14.0_0.darwin_19.x86_64.tbz2 from http://aus.us.packages.macports.org/macports/packages/valgrind
--->  Fetching distfiles for valgrind
Error: valgrind @3.14.0 is only compatible with macOS versions from 10.5 up to 10.13.
Error: Failed to fetch valgrind: incompatible macOS version
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_valgrind/valgrind/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port valgrind failed

The current release version of Valgrind is 3.15.0 according to the home page.

[raimue (Rainer Müller)]

valgrind is at 3.16.1, so I assume we can close this request.