net/gcoap: fix vera++ code style warnings
net/gcoap: fix vera++ code style warnings

OTAkeys/RIOT,ant9000/RIOT,smlng/RIOT,basilfx/RIOT,ant9000/RIOT,kYc0o/RIOT,jasonatran/RIOT,kaspar030/RIOT,kaspar030/RIOT,kaspar030/RIOT,ant9000/RIOT,kYc0o/RIOT,basilfx/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,miri64/RIOT,yogo1212/RIOT,miri64/RIOT,authmillenon/RIOT,smlng/RIOT,kaspar030/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,ant9000/RIOT,yogo1212/RIOT,miri64/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,ant9000/RIOT,OTAkeys/RIOT,yogo1212/RIOT,authmillenon/RIOT,authmillenon/RIOT,OTAkeys/RIOT,kYc0o/RIOT,kYc0o/RIOT,miri64/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,smlng/RIOT,smlng/RIOT,OlegHahm/RIOT,jasonatran/RIOT,yogo1212/RIOT,authmillenon/RIOT,kaspar030/RIOT,basilfx/RIOT,authmillenon/RIOT,smlng/RIOT,basilfx/RIOT,kYc0o/RIOT,authmillenon/RIOT,OTAkeys/RIOT,yogo1212/RIOT,yogo1212/RIOT,basilfx/RIOT,miri64/RIOT