ZDI Public Numbers can be 4 digits, ZDI-19-1045

Also, technically, ZDI Public Numbers will always have a min of 3 digits.
The number is essentially `"num_as_string".ljust(3, '0')`, so this should be {3,4}
or {3,5} if they ever get that high ;) I could find no ZDI- references or similar that
only had 2 digits in the last number part

references:
https://www.zerodayinitiative.com/advisories/ZDI-19-1045/
https://www.zerodayinitiative.com/advisories/ZDI-05-001/

tools/dev/msftidy.rb

@@ -178,7 +178,7 @@ class Msftidy
         when 'US-CERT-VU'
           warn("Invalid US-CERT-VU reference") if value !~ /^\d+$/
         when 'ZDI'
-          warn("Invalid ZDI reference") if value !~ /^\d{2}-\d{3}$/
+          warn("Invalid ZDI reference") if value !~ /^\d{3}-\d{4}$/
         when 'WPVDB'
           warn("Invalid WPVDB reference") if value !~ /^\d+$/
         when 'PACKETSTORM'