reportbooru: raise exception if not configured.

app/logical/missed_search_service.rb

@@ -1,5 +1,15 @@
 # queries reportbooru to find missed post searches
 class MissedSearchService
+  def self.enabled?
+    Danbooru.config.reportbooru_server.present?
+  end
+
+  def initialize
+    if !MissedSearchService.enabled?
+      raise NotImplementedError.new("the Reportbooru service isn't configured. Missed searches are not available.")
+    end
+  end
+
   def each_search(&block)
     fetch_data.scan(/(.+?) (\d+)\.0\n/).each(&block)
   end

app/logical/popular_search_service.rb

@@ -2,7 +2,15 @@
 class PopularSearchService
   attr_reader :date, :scale
 
+  def self.enabled?
+    Danbooru.config.reportbooru_server.present?
+  end
+
   def initialize(date, scale)
+    if !PopularSearchService.enabled?
+      raise NotImplementedError.new("the Reportbooru service isn't configured. Popular searches are not available.")
+    end
+
     @date = date
     @scale = scale
   end

app/logical/reports/user_similarity.rb

@@ -24,7 +24,7 @@ module Reports
     end
 
     def fetch_similar_user_ids(endpoint = "user_similarity")
-      return NotImplementedError unless Danbooru.config.reportbooru_server
+      raise NotImplementedError.new("the Reportbooru service isn't configured. User similarity is not available.") unless Danbooru.config.reportbooru_server
 
       params = {
         "key" => Danbooru.config.reportbooru_key,