Handle false return by tiny_tds if connection fails

Author: aidanharan

lib/active_record/connection_adapters/sqlserver/database_statements.rb

@@ -350,7 +350,9 @@ def sp_executesql_sql(sql, types, params, name)
         def raw_connection_do(sql)
           case @connection_options[:mode]
           when :dblib
-            @connection.execute(sql).do
+            result = @connection.execute(sql)
+            raise ActiveRecordError, 'Database connection has failed' if result == false
+            result.do
           end
         ensure
           @update_sql = false