SNR Improvement

patch attached

please also update SNR-SWITCH-MIB

https://data.nag.wiki/SNR%20Switches/MIBs/SNR-SWITCH_private_2.1.121.mib

wget https://data.nag.wiki/SNR%20Switches/MIBs/SNR-SWITCH_private_2.1.121.mib -O /opt/observium/mibs/snr/SNR-SWITCH-MIB

changes:

• SNR-SWITCH-MIB (dcn/dcn-xxx.php) – add discovery for FLASH (storage) – need MIB update
• SNR-SWITCH-MIB (dcn/dcn-xxx.php) – do not discover CPU/memory/temperature from system in STACK mode
• SNR-SWITCH-MIB (snr.inc.php) – discovery CPU/memory/temperature from sysSlotTable when in STACK mode
• SNR-ERD* – add discover IPv4 address
• update discovery for SNR-SWITCH – new version style
• Add SNR RU SWITCH – another platform, but partially support SNR-SWITCH-MIB (same oids)