dist/debian: depends openjdk-8 specifically
dist/debian: depends openjdk-8 specifically

scylla-tools currently depends to default-jre, but it may
openjdk-11 on newer version of distributions, but we need openjdk-8.
So drop default-jre, use openjdk-8.

Fixes scylladb/scylla#4548

Message-Id: <6f3ae9271998ab72548b16e527653b7d69a238e9@scylladb.com>

scylladb/scylla-tools-java,scylladb/scylla-tools-java,scylladb/scylla-tools-java,scylladb/scylla-tools-java