Avoid using a prepared statement for ".stats on" after it has been closed

by the ".eqp full" logic.  Fix for ticket [7be932dfa60a8a6b3b26bcf76].

FossilOrigin-Name: bb87c054b1b76959e46258ac66b24027f468b390a4148ac67f208a1fbeda4060

src/shell.c.in

@@ -2972,6 +2972,7 @@ static int shell_exec(
           /* Reprepare pStmt before reactiving trace modes */
           sqlite3_finalize(pStmt);
           sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+          if( pArg ) pArg->pStmt = pStmt;
         }
         restore_debug_trace_modes();
       }