FIX: Use linkahead library for internal variables

setup.cfg

@@ -20,8 +20,8 @@ packages = find:
 python_requires = >=3.7
 install_requires =
 	importlib-resources
-	caosdb > 0.11.2
 	caosadvancedtools >= 0.7.0
+    linkahead
     yaml-header-tools >= 0.2.1
     pyyaml
     odfpy #make optional

src/caoscrawler/config.py

@@ -17,7 +17,7 @@
 # along with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 
-import caosdb as db
+import linkahead as db
 
 DEFAULTS = {
     "send_crawler_notifications": False,