Removes validation of pname

https://dev.metasploit.com/redmine/issues/8119

- [x] Specs pass for metasploit_data_models
- [x] Specs pass on MSF PR: https://github.com/rapid7/metasploit-framework/pull/2112
- [x] Specs pass on Pro PR: https://github.com/rapid7/pro/pull/877
- [ ] Merge this PR
- [ ] Locally, in mdm checkout, pull master and `rake release` to publish metasploit_data_models to rubygems
- [ ] Add 'Jenkins test this please' to Pro PR: https://github.com/rapid7/pro/pull/877
- [ ] For MSF, you will need to sign into Travis CI and trigger a restart build on the build that failed. You will need to be an admin on https://travis-ci.org/rapid7/metasploit-framework or ask one (Luke, Sam, Brandon)
- [ ] MSF passes Travis CI
- [ ] Jenkins passes Pro
- [ ] Merge MSF PR: https://github.com/rapid7/metasploit-framework/pull/2112
- [ ] Merge Pro PR: https://github.com/rapid7/pro/pull/877
- [ ] [Release the Java version](https://github.com/rapid7/pro/wiki/MDM-gem#java-gem)