dmtcp: 2.5.1 -> 2.5.2

Semi-automatic update. These checks were performed:

- built on NixOS
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm -h` got 0 exit code
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm --help` got 0 exit code
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm -V` and found version 2.5.2
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm -v` and found version 2.5.2
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm --version` and found version 2.5.2
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm -h` and found version 2.5.2
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_discover_rm --help` and found version 2.5.2
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_rm_loclaunch -h` got 0 exit code
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_rm_loclaunch --help` got 0 exit code
- ran `/nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2/bin/dmtcp_rm_loclaunch help` got 0 exit code
- found 2.5.2 with grep in /nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2
- found 2.5.2 in filename of file in /nix/store/dpqcx4vr2nzam3c504xg5qc0rmmf1c4k-dmtcp-2.5.2