[v10.0.x] Variables: Remount query editor when datasource changed (#70745)

Variables: Remount query editor when datasource changed (#70615)

(cherry picked from commit 6c900b84bd)

Co-authored-by: kay delaney <45561153+kaydelaney@users.noreply.github.com>

public/app/features/variables/query/QueryVariableEditor.tsx

@@ -152,6 +152,7 @@ export class QueryVariableEditorUnConnected extends PureComponent<Props, State>
       return (
         <Field label="Query">
           <VariableQueryEditor
+            key={datasource.uid}
             datasource={datasource}
             query={query}
             templateSrv={getTemplateSrv()}
@@ -167,6 +168,7 @@ export class QueryVariableEditorUnConnected extends PureComponent<Props, State>
       return (
         <Field label="Query">
           <VariableQueryEditor
+            key={datasource.uid}
             datasource={datasource}
             query={query}
             onChange={this.onQueryChange}