client could be more verbose on config error

When I have a "sshPort=" (empty) property then client.bat/sh will not use the default port. Whats worse is, that the resulting error (even when -p is specified) does not tell me what config file and what option is the problem:

    Exception in thread "main" java.lang.NumberFormatException: For input string: ""
            at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
            at java.lang.Integer.parseInt(Integer.java:592)
            at java.lang.Integer.parseInt(Integer.java:615)
            at org.apache.karaf.client.ClientConfig.getInt(ClientConfig.java:238)
            at org.apache.karaf.client.ClientConfig.<init>(ClientConfig.java:60)
            at org.apache.karaf.client.Main.main(Main.java:76)

I am willing to provide a patch which adds the property name to this exception. However I think for trimmed empty properties it should fall back to the default as well.

Question: what about invalid (non-numeric) content? Should it also fall back to the default (asuming it might be even overwritten on the command line) as well or should we keep the (enhanced) exception?