monitoring: Fix query class names not matching the file name

modules/monitoring/library/Monitoring/Backend/Ido/Query/EventhistoryQuery.php

@@ -9,7 +9,7 @@ use Icinga\Data\Filter\Filter;
 /**
  * Query for event history records
  */
-class EventHistoryQuery extends IdoQuery
+class EventhistoryQuery extends IdoQuery
 {
     /**
      * {@inheritdoc}

modules/monitoring/library/Monitoring/Backend/Ido/Query/GroupsummaryQuery.php

@@ -8,7 +8,7 @@ use Zend_Db_Select;
 /**
  * Query for host and service group summaries
  */
-class GroupSummaryQuery extends IdoQuery
+class GroupsummaryQuery extends IdoQuery
 {
     /**
      * {@inheritdoc}

modules/monitoring/library/Monitoring/Backend/Ido/Query/StatussummaryQuery.php

@@ -10,7 +10,7 @@ use Icinga\Data\Filter\Filter;
 /**
  * Query for host and service status summary
  */
-class StatusSummaryQuery extends IdoQuery
+class StatussummaryQuery extends IdoQuery
 {
     /**
      * {@inheritdoc}