Another stab at fixing Muse detection on Linux

src/calibre/devices/cybook/driver.py

@@ -129,3 +129,10 @@ class MUSE(CYBOOK):
 
     EBOOK_DIR_MAIN = 'Books'
     SCAN_FROM_ROOT = True
+
+    @classmethod
+    def can_handle(cls, device_info, debug=False):
+        if isunix:
+            return device_info[3] == 'Bookeen' and device_info[4] == 'Cybook'
+        return True
+