SDCardScannerService causes BackgroundServiceStartNotAllowedException
This is 1.17-alpha0 full flavor:
``` ruby
06-30 14:37:54.258 9845 9845 E ACRA : ACRA caught a RuntimeException for org.fdroid.fdroid.debug
06-30 14:37:54.258 9845 9845 E ACRA : java.lang.RuntimeException: Unable to create application org.fdroid.fdroid.FDroidApp: android.app.BackgroundServiceStartNotAllowedException: Not allowed to start service Intent { act=org.fdroid.fdroid.nearby.SCAN cmp=org.fdroid.fdroid.debug/org.fdroid.fdroid.nearby.SDCardScannerService }: app is in background uid UidRecord{9407237 u0a188 TRNB idle change:procadj procs:0 seq(16858,16822)}
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6776)
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ActivityThread.-$$Nest$mhandleBindApplication(Unknown Source:0)
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2129)
06-30 14:37:54.258 9845 9845 E ACRA : at android.os.Handler.dispatchMessage(Handler.java:106)
06-30 14:37:54.258 9845 9845 E ACRA : at android.os.Looper.loopOnce(Looper.java:201)
06-30 14:37:54.258 9845 9845 E ACRA : at android.os.Looper.loop(Looper.java:288)
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ActivityThread.main(ActivityThread.java:7884)
06-30 14:37:54.258 9845 9845 E ACRA : at java.lang.reflect.Method.invoke(Native Method)
06-30 14:37:54.258 9845 9845 E ACRA : at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
06-30 14:37:54.258 9845 9845 E ACRA : at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)
06-30 14:37:54.258 9845 9845 E ACRA : Caused by: android.app.BackgroundServiceStartNotAllowedException: Not allowed to start service Intent { act=org.fdroid.fdroid.nearby.SCAN cmp=org.fdroid.fdroid.debug/org.fdroid.fdroid.nearby.SDCardScannerService }: app is in background uid UidRecord{9407237 u0a188 TRNB idle change:procadj procs:0 seq(16858,16822)}
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ContextImpl.startServiceCommon(ContextImpl.java:1908)
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ContextImpl.startService(ContextImpl.java:1864)
06-30 14:37:54.258 9845 9845 E ACRA : at android.content.ContextWrapper.startService(ContextWrapper.java:817)
06-30 14:37:54.258 9845 9845 E ACRA : at org.fdroid.fdroid.nearby.SDCardScannerService.scan(SDCardScannerService.java:80)
06-30 14:37:54.258 9845 9845 E ACRA : at org.fdroid.fdroid.FDroidApp.onCreate(FDroidApp.java:398)
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1281)
06-30 14:37:54.258 9845 9845 E ACRA : at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6771)
06-30 14:37:54.258 9845 9845 E ACRA : ... 9 more
```
issue