Listing agent instructions gives an error

To reproduce:

1. Goto Schedule build
2. List configurations
3. Click "Show" on a configuration

2017-09-17 19:48:58,637 ERROR:server: Can't convert 'NoneType' object to str implicitly
Traceback (most recent call last):
  File "/home/citest/baseline-testing/tqtc-coin-ci/env/lib/python3.5/site-packages/thriftpy/server.py", line 92, in handle
    self.processor.process(iprot, oprot)
  File "/home/citest/baseline-testing/tqtc-coin-ci/env/lib/python3.5/site-packages/thriftpy/thrift.py", line 240, in process
    self.handle_exception(e, result)
  File "/home/citest/baseline-testing/tqtc-coin-ci/env/lib/python3.5/site-packages/thriftpy/thrift.py", line 237, in process
    result.success = call()
  File "/home/citest/baseline-testing/tqtc-coin-ci/env/lib/python3.5/site-packages/thriftpy/thrift.py", line 202, in <lambda>
    *(args._dict_[k] for k in api_args)
  File "src/platform_configurations.py", line 287, in get_agent_instructions
    return module.instructions(moduleConfig)
  File "/home/citest/baseline-testing/tqtc-coin-ci/src/modules.py", line 180, in instructions
    return self.build_instructions(platformInstructions, moduleConfig)
  File "/home/citest/baseline-testing/tqtc-coin-ci/src/modules.py", line 269, in build_instructions
    platformInstructions.installDependencies(moduleConfig.testConfiguration, moduleConfig.repositoryState)
  File "/home/citest/baseline-testing/tqtc-coin-ci/src/platforminstructions.py", line 293, in installDependencies
    self.installSourceArchive(repositoryState, windowsLineFeeds)
  File "/home/citest/baseline-testing/tqtc-coin-ci/src/platforminstructions.py", line 273, in installSourceArchive
    m.filename = LocalStorage.sourcesFilePath(repository.project, repository.sha1, windowsLineFeeds=windowsLineFeeds, excludeSubModules=excludeSubModules)
  File "/home/citest/baseline-testing/tqtc-coin-ci/src/storage.py", line 184, in sourcesFilePath
    return storagePath + "/" + project + "/" + sha1 + ("/sources%s_%s.tar.gz" % (suffix, lineFeeds))
TypeError: Can't convert 'NoneType' object to str implicitly