deb: fix extraction of uncompressed data.tar (#21)

In some debian packages the data.tar is not compressed
and named only data.tar without any extension.

ebcl/common/deb.py

@@ -97,7 +97,12 @@ def extract(self, location: Optional[str] = None,
             return None
 
         # find data.tar
-        tar_files = list(Path(deb_content_location).glob('data.tar.*'))
+        data_tar = Path(deb_content_location) / 'data.tar'
+        if data_tar.exists():
+            tar_files = [data_tar]
+        else:  # find compressed data.tar
+            tar_files = list(Path(deb_content_location).glob('data.tar.*'))
+
         if not tar_files:
             logging.error('No tar content found in package %s!', self)
             return None