Added support for unwrapped jar

[renelink]

The jar file must not be added to the launch4j config if dontWrapJar is
enabled. Otherwise it would result in a

net.sf.launch4j.BuilderException: Specify runtime path of the jar relative
to the executable.

[lukaszlenart]

LGTM 👍

[gino0631]

I'm afraid this is wrong.

As per documentation, it is OK to specify a jar and set dontWrapJar to true, and after upgrade to 1.7.17 I started getting:
net.sf.launch4j.BuilderException: Specify runtime path of a jar or the classpath.

[lukaszlenart]

hm... @gino0631 looks like you are right, I will revert to the previous behaviour.

[TheLQ]

.17 with dontWrapJar=true doesn't seem to make a usable executable. In my case the exe is built but when ran it just exits immediately or the Java help is shown to the console.