[FIX] Don't use hardcoded secret key for JWT

gargantext/settings.py

@@ -180,7 +180,7 @@ REST_FRAMEWORK = {
 JWT_AUTH = {
     'JWT_PAYLOAD_HANDLER': 'gargantext.util.jwt.jwt_payload_handler',
     'JWT_VERIFY_EXPIRATION': True,
-    'JWT_SECRET_KEY': 'Mw/q=efK3ai7}?}?!D68}a2.j}G5;1]ceI;OV1l=N^(-mH+%l=',
+    'JWT_SECRET_KEY': config('SECRET_KEY'),
     'JWT_EXPIRATION_DELTA': datetime.timedelta(seconds=36000),
     'JWT_AUTH_HEADER_PREFIX': 'Bearer',
 }