Local configurations not applied when using ConfiguredGraphFactory

[rngcntr]

When creating Graphs using ConfiguredGraphFactory, a TemplateConfiguration is used to generate a configuration for each graph. Once a graph is created, its configuration is manifested and can not be changed later on by providing different environment variables.
We noticed this issue specifically when trying to set graph.replace-instance-if-exists. According to the documentation, it should be allowed to operate two JanusGraph instances on the same graph and have both use different settings for graph.replace-instance-if-exists. However, with ConfiguredGraphFactory, this is not the case. Judging from the code, other configuration options are affected as well.

• Version: 1.0.0
• Storage Backend: any
• Mixed Index Backend: any
• Expected Behavior: LOCAL settings are read from environment variables and applied to all graphs
• Current Behavior: Any settings from environment variables are ignored for all graphs
• Steps to Reproduce:
  1. Start JanusGraph instance with local setting key=value1
  2. Create TemplateConfiguration with ConfiguredGraphFactory
  3. Create a graph using ConfiguredGraphFactory
  4. Shutdown JanusGraph instance and start a new instance with local setting key=value2
  5. The previously created graph is now still running with key=value1 instead of key=value2.