[pgAdmin4][Patch]: Clear the content of message tab properly

[Murtuza Zabuawala]

Hi,

PFA patch to fix the issue where the content of message tab was not getting
cleared after user executes Explain and Explain Analyze option from query
tool.
RM#2974

--
Regards,
Murtuza Zabuawala
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

diff --git a/web/pgadmin/static/js/sqleditor/query_tool_actions.js 
b/web/pgadmin/static/js/sqleditor/query_tool_actions.js
index a376f01..5757e36 100644
--- a/web/pgadmin/static/js/sqleditor/query_tool_actions.js
+++ b/web/pgadmin/static/js/sqleditor/query_tool_actions.js
@@ -36,6 +36,7 @@ let queryToolActions = {
     let buffers = this._buffers();
     let timing = this._timing();
     let explainAnalyzeQuery = `EXPLAIN (FORMAT JSON, ANALYZE ON, VERBOSE 
${verbose}, COSTS ${costEnabled}, BUFFERS ${buffers}, TIMING ${timing}) `;
+    this._clearMessageTab();
     sqlEditorController.execute(explainAnalyzeQuery);
   },
 
@@ -44,6 +45,7 @@ let queryToolActions = {
     let verbose = this._verbose();
 
     let explainQuery = `EXPLAIN (FORMAT JSON, ANALYZE OFF, VERBOSE ${verbose}, 
COSTS ${costEnabled}, BUFFERS OFF, TIMING OFF) `;
+    this._clearMessageTab();
     sqlEditorController.execute(explainQuery);
   },