Conflict resolver: Does not find conflicts in files without extension

[pilcru]

If you get a conflict in a file that has no dot in its name (for example myfile), Syncthing will create a conflict file named like myfile.sync-conflict-20060102-150405-ABCDEF. The conflict resolver in Synctrayzor is then unable to find this conflict because it expects a second dot and an extension in the conflict name, after ABCDEF.

I'm sending a PR that updates the base regex of the conflict resolver to fix this.

Synctrayzor version: 2.1.0
Syntching version: 2.0.13