Sometimes an expression `versionFile.readText()`
returns an empty string, so that `toInt()` fails
with `NumberFormatException`.
It can happen in with both JPS and Gradle.
I could not reproduce the problem,
and it seems to be impossible (under normal circumstances),
because we always write a non-empty string,
and the file is checked to exist before reading.
Maybe it could be caused by an FS error.
The only "solution" to the problem I could think
is to swallow the exception, and assume
that cache version is not valid (so it would cause a rebuild of a module).
#KT-17125 fixed
Alexey Tsvetkov
a047c3682a