replace cuckoo.compat.magic by sflock.magic

Since version 0.3.4 sflock features 64-bit Windows support for magic(5).
Now that we no longer need this compatibility layer (which was
equivalent to the one in sflock) we simply get rid of it.
It was required earlier because Cuckoo wasn't capable of requiring
updated libraries in the pre-Python package era.

cuckoo/common/objects.py

@@ -11,12 +11,12 @@
 import os
 import pefile
 import re
+import sflock
 import shutil
 import tempfile
 import zipfile
 
 from cuckoo.common.whitelist import is_whitelisted_domain
-from cuckoo.compat import magic
 
 try:
     import pydeep
@@ -224,13 +224,17 @@ def get_type(self):
         """Get MIME file type.
         @return: file type.
         """
-        return magic.from_file(os.path.realpath(self.file_path))
+        return sflock.magic.from_file(
+            os.path.realpath(self.file_path)
+        )
 
     def get_content_type(self):
         """Get MIME content file type (example: image/jpeg).
         @return: file content type.
         """
-        return magic.from_file(os.path.realpath(self.file_path), mime=True)
+        return sflock.magic.from_file(
+            os.path.realpath(self.file_path), mime=True
+        )
 
     def get_exported_functions(self):
         """Get the exported function names of this PE file."""