Use @kontroller instead of @controller

Accessing @controller var in view shows deprecation warning and is
treated as try to access current controller instance which in this
case is ExceptionNotifier::Notifier instance - not what we need.

Author: Marcin Kulik

lib/exception_notifier/notifier.rb

@@ -40,7 +40,7 @@ def exception_notification(env, exception)
       @env        = env
       @exception  = exception
       @options    = (env['exception_notifier.options'] || {}).reverse_merge(self.class.default_options)
-      @controller = env['action_controller.instance'] || MissingController.new
+      @kontroller = env['action_controller.instance'] || MissingController.new
       @request    = ActionDispatch::Request.new(env)
       @backtrace  = clean_backtrace(exception)
       @sections   = @options[:sections]
@@ -50,7 +50,7 @@ def exception_notification(env, exception)
         instance_variable_set("@#{name}", value)
       end
 
-      prefix   = "#{@options[:email_prefix]}#{@controller.controller_name}##{@controller.action_name}"
+      prefix   = "#{@options[:email_prefix]}#{@kontroller.controller_name}##{@kontroller.action_name}"
       subject  = "#{prefix} (#{@exception.class}) #{@exception.message.inspect}"
 
       mail(:to => @options[:exception_recipients], :from => @options[:sender_address], :subject => subject) do |format|

lib/exception_notifier/views/exception_notifier/exception_notification.text.erb

@@ -1,4 +1,4 @@
-A <%= @exception.class %> occurred in <%= @controller.controller_name %>#<%= @controller.action_name %>:
+A <%= @exception.class %> occurred in <%= @kontroller.controller_name %>#<%= @kontroller.action_name %>:
 
   <%= raw @exception.message %>
   <%= raw @backtrace.first %>
@@ -10,4 +10,4 @@ A <%= @exception.class %> occurred in <%= @controller.controller_name %>#<%= @co
         "#{title}\n\n#{summary.gsub(/^/, "  ")}\n\n"
       end
     end %>
-<%= raw sections.join %>
+<%= raw sections.join %>