Make use of Tycho 0.22 qualifiedVersion property.

In Tycho 0.22 there is new property qualifiedVersion which contains the
unqualifiedVersion if no qualifier or the concatenation of the two if
qualifier is not empty. Thus this logic can be removed from cbi.
See
http://git.eclipse.org/c/tycho/org.eclipse.tycho.git/tree/tycho-packaging-plugin/src/main/java/org/eclipse/tycho/buildversion/BuildQualifierMojo.java#n215
for implementation.

Change-Id: I9d7f62a6ed63f1070ab19ad7a4e95a496d8216e1