Bug: unable to change paged content child weights if all values are set to 1.

[antbrown]

If you accidentally set all weights to 1 using the IntegerWeightSelector, it is then impossible to change the value to anything other than 1.

I think this happens because https://github.com/Islandora/islandora/blob/2.x/src/Plugin/views/field/IntegerWeightSelector.php#L54 only populates all possible values for the select element if there is a blank value returned from $this->getValue($row).

I think it should maybe populate all possible values when the number of options is less than the total number of rows returned by the view.

[jordandukart]

Merged in Islandora/islandora#863.