Fixed Debian kernel cleaning

kernels_cleaner.py

@@ -63,7 +63,9 @@ def clean_kernels():
     try:
         current_str = out.split(' ')[2]
         if current_str.endswith('-generic'):
-            current_str = current_str[:-8]
+            current_str = current_str[:-len('-generic')]
+        elif current_str.endswith('-amd64'):
+            current_str = current_str[:-len('-amd64')]
         current = [int(v) for v in current_str.replace('-', '.').split('.')]
     except Exception as e:
         log(RED + 'Failed to get current kernel.' + DEFAULT + '\nError: ' + str(e), error=True)