M-AB-S: INI parsing may get stuck when manually edited with error

[LigH-de]

I wanted to test how ccache may cause #2782 so I edited build/media-autobuild_suite.ini manually. I changed ccache=1 and wanted to make it ccache=2 but accidentally deleted the = so the result was ccache2

When the suite started, it got stuck before printing any text output or calling the update script. So I guess the parser strictly assumes key=value pairs and hangs on any content not in this format.