Fix added_sys_path default setting

This commit removes the inner string quotation of the default value for the
added_sys_path setting. The inner quotes cause the value of the resulting
variable g:jedi#added_sys_path to be the sting "[]" instead of an empty list.

AUTHORS.txt

@@ -55,5 +55,6 @@ Brian Mego (@brianmego)
 Stevan Milic (@stevanmilic) <stevan.milic@yahoo.com>
 Konstantin Glukhov (@Konstantin-Glukhov)
 Seungchan An (@SeungChan92) <dev.issea1015@gmail.com>
+Thomas Blauth (@ThomasBlauth) <thomas.blauth@protonmail.com>
 
 @something are github user names.

autoload/jedi.vim

@@ -36,7 +36,7 @@ let s:default_settings = {
     \ 'quickfix_window_height': 10,
     \ 'force_py_version': "'auto'",
     \ 'environment_path': "'auto'",
-    \ 'added_sys_path': "'[]'",
+    \ 'added_sys_path': '[]',
     \ 'project_path': "'auto'",
     \ 'smart_auto_mappings': 0,
     \ 'use_tag_stack': 1