`git sync` requires ssh to be specified when setting 'to' repo on set-up

When setting up the 'from' and 'to' repositories for git-sync on the CLI, running the command below throws the following exception:

~/Dev/openJDK (master) $ git sync --from https://github.com/openjdk/jdk --to git@github.com:pconcannon/jdk.git

Exception in thread "main" java.lang.IllegalArgumentException: Illegal character in scheme name at index 3: git@github.com:pconcannon/jdk.git
at java.base/java.net.URI.create(URI.java:906)
at org.openjdk.skara.cli/org.openjdk.skara.cli.GitSync.sync(GitSync.java:194)
at org.openjdk.skara.cli/org.openjdk.skara.cli.GitSync.main(GitSync.java:321)
at org.openjdk.skara.cli/org.openjdk.skara.cli.GitSkara.main(GitSkara.java:198)
Caused by: java.net.URISyntaxException: Illegal character in scheme name at index 3: git@github.com:pconcannon/jdk.git
at java.base/java.net.URI$Parser.fail(URI.java:2938)
at java.base/java.net.URI$Parser.checkChars(URI.java:3109)
at java.base/java.net.URI$Parser.parse(URI.java:3135)
at java.base/java.net.URI.<init>(URI.java:623)
at java.base/java.net.URI.create(URI.java:904)
... 3 more

The current workaround for this is to specify `ssh` as follows `--to ssh://git@github.com/pconcannon/jdk.git`