Tools: fix AppAssembler memory setting
Tools: fix AppAssembler memory setting

The min JVM memory had been set to 512m but the max wasn't set.
Apparently AppAssembler doesn't automatically adjust the max above the
min, or it was inheriting invalid values somewhere, so the JVM was being
created with invalid memory settings.

Fixed by setting the max to 1024m.

scifio/scifio