Stop looking for nodejs when found
Stop looking for nodejs when found

A small fix for 6ce637045 to stop searching for nodejs
implementations when the first is found. This prevents an error
when you have a local nodejs but not the node:slim docker image.
(ref #45 and #39).

jeremiahsavage/cwltool,jeremiahsavage/cwltool,dleehr/cwltool,common-workflow-language/cwltool,SciDAP/cwltool,dleehr/cwltool,chapmanb/cwltool,SciDAP/cwltool,dleehr/cwltool,SciDAP/cwltool,SciDAP/cwltool,common-workflow-language/cwltool,chapmanb/cwltool,chapmanb/cwltool,dleehr/cwltool,jeremiahsavage/cwltool,chapmanb/cwltool,common-workflow-language/cwltool,jeremiahsavage/cwltool