misc-package-update scanner hints incorrect summary

[navidshaikh]

Take a look at following excerpts from misc_package_updates_scanner_results

        {
            "CVE Feed Last Updated": "NA", 
            "Finished Time": "2018-03-24-02-48-40-153976", 
            "Scan Results": {
                "gem package updates": []
            }, 
            "Scan Type": "gem-updates", 
            "Scanner": "Misc Package Updates", 
            "Start Time": "2018-03-24-02-48-36-936122", 
            "Successful": "true", 
            "Summary": "Possible updates for packages installed via gem. ", 
            "UUID": "95d1de5eaab41c6627222a3021850f3006b2f00bfa1dac7def640768ecffbf18"
        }
    ], 
    "msg": "Possible updates for packages installed via gem. ", 
    "scanner_name": "misc-package-updates"

Even if there are no gem_package_updates available, the Summary says "Possible updates for packages installed via gem. ".

[navidshaikh]

Fixed by #546