examples/nimble_gatt: fix typos
examples/nimble_gatt: fix typos

aeneby/RIOT,mtausig/RIOT,authmillenon/RIOT,kaspar030/RIOT,authmillenon/RIOT,mtausig/RIOT,OTAkeys/RIOT,miri64/RIOT,basilfx/RIOT,RIOT-OS/RIOT,yogo1212/RIOT,josephnoir/RIOT,authmillenon/RIOT,basilfx/RIOT,kaspar030/RIOT,basilfx/RIOT,x3ro/RIOT,OTAkeys/RIOT,smlng/RIOT,miri64/RIOT,yogo1212/RIOT,authmillenon/RIOT,aeneby/RIOT,OlegHahm/RIOT,toonst/RIOT,toonst/RIOT,josephnoir/RIOT,kaspar030/RIOT,smlng/RIOT,yogo1212/RIOT,mtausig/RIOT,smlng/RIOT,josephnoir/RIOT,jasonatran/RIOT,OTAkeys/RIOT,yogo1212/RIOT,OlegHahm/RIOT,ant9000/RIOT,basilfx/RIOT,jasonatran/RIOT,kYc0o/RIOT,ant9000/RIOT,kaspar030/RIOT,kaspar030/RIOT,mtausig/RIOT,toonst/RIOT,authmillenon/RIOT,x3ro/RIOT,jasonatran/RIOT,josephnoir/RIOT,smlng/RIOT,kYc0o/RIOT,OTAkeys/RIOT,kYc0o/RIOT,toonst/RIOT,miri64/RIOT,authmillenon/RIOT,aeneby/RIOT,toonst/RIOT,x3ro/RIOT,ant9000/RIOT,yogo1212/RIOT,miri64/RIOT,kYc0o/RIOT,josephnoir/RIOT,ant9000/RIOT,smlng/RIOT,RIOT-OS/RIOT,mtausig/RIOT,yogo1212/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,ant9000/RIOT,kYc0o/RIOT,x3ro/RIOT,x3ro/RIOT,basilfx/RIOT,miri64/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,aeneby/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,OTAkeys/RIOT,aeneby/RIOT