Reproduction steps:
1. Download user's project and open in Unity
2. From folder of the project open the "BambooTree.fbx.meta" (with notepad++)
3. In Unity reimport the "BambooTree" model

Expected: no warnings in the console and after reimporting a model no lines should appear in the metafile
Actual: warnings in the console appear and lines like "2186277476908879412: ImportLogs" appear in metafile after reimporting a model

Reproduced on: 2018.1.0b6; 2018.2.0a1

Note:
5.6.5p1, 2017.1.3p1, 2017.2.1p3, 2017.3.1f1 will not add a line to the metafile.
Doing reproduction steps with the different model will result in different warnings.