Fix MLCP examples to not use https for ML Maven repo

[rjrudin]

[mariannemyers]

This fix should prevent the following error. As a workaround in the interim, change the repository url for ML maven to be maven { url "http://developer.marklogic.com/maven2/" }

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':mlLoadContent'.
> Could not resolve all files for configuration ':mlcp'.
   > Could not download commons-csv.jar (org.apache.commons:commons-csv:1.5.1-marklogic)
      > Could not get resource 'https://developer.marklogic.com/maven2/org/apache/commons/commons-csv/1.5.1-marklogic/commons-csv-1.5.1-marklogic.jar'.
         > Could not GET 'https://developer.marklogic.com/maven2/org/apache/commons/commons-csv/1.5.1-marklogic/commons-csv-1.5.1-marklogic.jar'.
            > sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target