scripts: filter-known-issues: Add extra newline
scripts: filter-known-issues: Add extra newline

For better readability, add an extra newline when printing the result of
filtering a log.

Signed-off-by: Carles Cufi <853081dc8dca4fe6a7e3c984752718b5db36e060@nordicsemi.no>

galak/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,explora26/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,galak/zephyr,kraj/zephyr,nashif/zephyr,ldts/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,Vudentz/zephyr,nashif/zephyr,ldts/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,punitvara/zephyr,ldts/zephyr,ldts/zephyr,nashif/zephyr,galak/zephyr,Vudentz/zephyr,punitvara/zephyr,kraj/zephyr,nashif/zephyr,punitvara/zephyr,nashif/zephyr,kraj/zephyr,explora26/zephyr,explora26/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,galak/zephyr,kraj/zephyr