`helm:template` with `additionalArguments` is broken since 6.6.0

[Stephan Schnabel]

If additionalArguments contains spaces this will break if used with Runtime.getRuntime().exec(String[]).

Log statement:

Error: unknown flag: --output-dir /home/ssc/code/kokuwa/helm-maven-plugin/target/it/template-with-additional-arguments/target/custom-helm-output

Should be splitted.