net: app: Close context even if there is no connection
net: app: Close context even if there is no connection

If there is no connection to server, then _net_app_select_net_ctx()
will return NULL. This is perfectly fine and we can just continue.

Signed-off-by: Jukka Rissanen <f9f077d1da4c7aa947f9864fa5a28c3588f6a45d@linux.intel.com>

explora26/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,fbsder/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,punitvara/zephyr,galak/zephyr,zephyriot/zephyr,galak/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,finikorg/zephyr,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,mbolivar/zephyr,punitvara/zephyr,nashif/zephyr,punitvara/zephyr,nashif/zephyr,punitvara/zephyr,finikorg/zephyr,fbsder/zephyr,punitvara/zephyr,aceofall/zephyr-iotos,kraj/zephyr,zephyriot/zephyr,nashif/zephyr,fbsder/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,aceofall/zephyr-iotos,galak/zephyr,zephyriot/zephyr,nashif/zephyr,zephyriot/zephyr,nashif/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,zephyriot/zephyr,Vudentz/zephyr,mbolivar/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,kraj/zephyr,explora26/zephyr,Vudentz/zephyr,mbolivar/zephyr,kraj/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,aceofall/zephyr-iotos,explora26/zephyr,mbolivar/zephyr,finikorg/zephyr,fbsder/zephyr,Vudentz/zephyr,fbsder/zephyr,aceofall/zephyr-iotos,explora26/zephyr,galak/zephyr,kraj/zephyr,Vudentz/zephyr,galak/zephyr,ldts/zephyr,finikorg/zephyr,ldts/zephyr