Update SoSy-Lab Common Lib
This makes sure that ConfigurationOptions.txt gets a proper license
header as soon as machine-readable headers are added to the Java
sources.
<dependencies>
<!-- SoSy-Lab Common Library -->
- <dependency org="org.sosy_lab" name="common" rev="0.3000-392-g680ac82" conf="runtime->runtime; contrib->sources"/>
+ <dependency org="org.sosy_lab" name="common" rev="0.3000-420-gef84297" conf="runtime->runtime; contrib->sources"/>
<!-- Google Core Libraries for Java
Contains a lot of helpful data structures. -->
