B#1557 onedb fsck breaks the resources when they contain non-ASCII chars (#2200)

src/onedb/onedb_backend.rb

@@ -305,6 +305,13 @@ class BackEndMySQL < OneDBBacKEnd
 
         begin
             @db = Sequel.connect(endpoint)
+
+            encoding = "utf8mb4"
+            @db.fetch("SELECT @@CHARACTER_SET_DATABASE;") do |row|
+                encoding = row[:@@CHARACTER_SET_DATABASE]
+            end
+
+            @db = Sequel.connect(endpoint + "?encoding=#{encoding}")
         rescue Exception => e
             raise "Error connecting to DB: " + e.message
         end