Manifest header for OSGi Import-Package of akka package should allow range up to next minor version

[michael-smith]

The built akka-http libraries are incompatible with any akka library that is 2.5.0 and above because the generation of the Import-Package for akka defines a range that goes from the current dependent patch version up to (but not including) the next minor version.

This should be changed so that is allows a range from the current lowest dependent version up to, but not including, the next major version.

For example, instead of the range being [2.4.17, 2.5.0), it should be [2.4.17, 3.0.0)