remove unused import

src/vs/workbench/contrib/debug/browser/repl.ts

@@ -50,7 +50,6 @@ import { ITextResourcePropertiesService } from 'vs/editor/common/services/textRe
 import { RunOnceScheduler } from 'vs/base/common/async';
 import { FuzzyScore } from 'vs/base/common/filters';
 import { IClipboardService } from 'vs/platform/clipboard/common/clipboardService';
-import { PANEL_BACKGROUND } from 'vs/workbench/common/theme';
 import { ReplDelegate, ReplVariablesRenderer, ReplSimpleElementsRenderer, ReplEvaluationInputsRenderer, ReplEvaluationResultsRenderer, ReplRawObjectsRenderer, ReplDataSource, ReplAccessibilityProvider, ReplGroupRenderer } from 'vs/workbench/contrib/debug/browser/replViewer';
 import { localize } from 'vs/nls';
 import { ViewPane, IViewPaneOptions } from 'vs/workbench/browser/parts/views/viewPaneContainer';