examples/dtls-echo: remove TINYDTLS_LOG and use DTLS_DEBUG
examples/dtls-echo: remove TINYDTLS_LOG and use DTLS_DEBUG

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