Fix crash caused by infinite loop
Fix crash caused by infinite loop

When there is no data in the changeset table, Source_Date_Select()
goes into an infinite loop and crashes as PHP runs out of memory.

make-all/source-integration,make-all/source-integration,dregad/source-integration,mantisbt-plugins/source-integration,bright-tools/source-integration,bright-tools/source-integration-fixes,bright-tools/source-integration,morgant/source-integration,morgant/source-integration,morgant/source-integration,make-all/source-integration,dregad/source-integration,bright-tools/source-integration-fixes,bright-tools/source-integration,mantisbt-plugins/source-integration,bright-tools/source-integration,mantisbt-plugins/source-integration,dregad/source-integration,bright-tools/source-integration-fixes