[BUGFIX] Change backend index queue amount to 10

[georgringer]

In a246cb8e34d80da6227445c0c800620f16264a00 the amount changed to 1 but should be 10. In the long run it should be configurable

[dkd-kaehm]

IMHO we do not want 10 Items, because this button is for debugging purposes only. I would propose to mark this button with the hint.