An unnecessary assert in ThreadedHsqlEpsgFactory prevents the use of an EPSG HSQL database in path with spaces. This situation occurs when, for example, building in a path with spaces with -Djava.io.tmpdir=target. The assert contradicts the comment at the top of the enclosing if block, which discusses HSQLDB not accepting percent-encoded spaces in its URLs, and then the assert tries to round-trip the invalid HSQLDB URL through the URL class, which fails because of percent-encoding. The solution is to remove the assert.
Merged on master.
Cherry-picked onto 19.x and 18.x.