Errors are shown in third-party packages with inline annotations when using daemon

[ilevkivskyi]

To reproduce:

• Start daemon on a code that uses e.g. pytest before installing pytest
• Install pytest (it has inline annotations)
• Run dmypy run again and get a lot of error messages.

[ilevkivskyi]

Note that restarting the daemon fixes the issue.

[JukkaL]

This also happens with types-* packages. For example:

• Start daemon on a file that imports requests using --disallow-untyped-defs
• Install types-requests
• Run dmypy run and get lots of errors

Again restarting the daemon helps.