make fdroid verify use common.verify_apks()

This makes the jarsigner the ultimate and only judge of whether two APKs
match.  This is the best tool since APK signatures are jar signatures. This
should be eventually updated to use the official Android APK signing tool
called apksigner.

https://android.googlesource.com/platform/tools/apksig/

fdroidserver/verify.py

@@ -78,9 +78,9 @@ def main():
             logging.info("...retrieving " + url)
             net.download_file(url, dldir=tmp_dir)
 
-            compare_result = common.compare_apks(
-                os.path.join(unsigned_dir, apkfilename),
+            compare_result = common.verify_apks(
                 remoteapk,
+                os.path.join(unsigned_dir, apkfilename),
                 tmp_dir)
             if compare_result:
                 raise FDroidException(compare_result)