Fix RemoteFileSupplier (#3683)

Author: CTMBNara

src/main/java/org/prebid/server/execution/file/supplier/RemoteFileSupplier.java

@@ -96,8 +96,8 @@ private Future<Boolean> isSizeChanged() {
     private Future<Void> downloadFile() {
         return fileSystem.open(tmpPath, new OpenOptions())
                 .compose(tmpFile -> sendHttpRequest(getRequestOptions)
-                        .compose(response -> response.pipeTo(tmpFile))
-                        .onComplete(result -> tmpFile.close()));
+                        .onFailure(ignored -> tmpFile.close())
+                        .compose(response -> response.pipeTo(tmpFile)));
     }
 
     private Future<HttpClientResponse> sendHttpRequest(RequestOptions requestOptions) {

src/test/java/org/prebid/server/execution/file/supplier/RemoteFileSupplierTest.java

@@ -125,6 +125,7 @@ public void getShouldReturnFailureOnNotOkStatusCode() {
         final Future<String> result = target.get();
 
         // then
+        verify(tmpFile).close();
         FutureAssertion.assertThat(result).isFailed()
                 .hasMessage("Got unexpected response from server with status code 204 and message null");
     }
@@ -147,7 +148,6 @@ public void getShouldReturnExpectedResult() {
         final Future<String> result = target.get();
 
         // then
-        verify(tmpFile).close();
         assertThat(result.result()).isEqualTo(SAVE_PATH);
     }
 
@@ -178,7 +178,6 @@ public void getShouldReturnExpectedResultWhenCheckRemoteFileSizeIsTrue() {
         final Future<String> result = target.get();
 
         // then
-        verify(tmpFile).close();
         assertThat(result.result()).isEqualTo(SAVE_PATH);
     }