limit number of '::' when parsing model name. It will prevent from in…

…finity loop inside regex when parsing strings like 'ManageIQ::Providers::CloudManagermanaged-se'

lib/miq_expression/tag.rb

@@ -1,6 +1,6 @@
 class MiqExpression::Tag < MiqExpression::Target
   REGEX = /
-(?<model_name>([[:alnum:]]*(::)?)*)
+(?<model_name>([[:alnum:]]*(::)?){4})
 \.?(?<associations>([a-z_]+\.)*)
 (?<namespace>\bmanaged|user_tag\b)
 -(?<column>[a-z]+[_[:alnum:]]+)