Bug#548074: When log4cxx creates a thread, it doesn't block signals it's not using, leading to unreliable signal delivery for the calling process.

[Tobias Frost]

Control: reassign -1 liblog4cxx11
Control: affects -1 liblog4cxx10
Control: affects -1 liblog4cxx12

> 
> Upstream is currently in preparation for a new release (0.12.1) where this
> problem is fixed.

Correction: The issue was not fixed in 12.1. (It will be fixed in 0.13.0.)