fix(alert_tab): better execution state description

public/app/features/alerting/partials/alert_tab.html

@@ -91,7 +91,7 @@
 				</div>
 
 				<div class="gf-form">
-          <span class="gf-form-label width-18">If query exeuction throws an error</span>
+          <span class="gf-form-label width-18">On execution error or timeout</span>
           <span class="gf-form-label query-keyword">SET STATE TO</span>
 					<div class="gf-form-select-wrapper">
 						<select class="gf-form-input" ng-model="ctrl.alert.executionErrorState" ng-options="f.value as f.text for f in ctrl.executionErrorModes">