Fix detection and removal of metadata.db ending in calibre-directory

Update requirements

cps/admin.py

@@ -780,7 +780,7 @@ def _configuration_update_helper():
     to_save = request.form.to_dict()
     gdriveError = None
 
-    to_save['config_calibre_dir'] = re.sub('[\\/]metadata\.db$',
+    to_save['config_calibre_dir'] = re.sub(r'[\\/]metadata\.db$',
                                            '',
                                            to_save['config_calibre_dir'],
                                            flags=re.IGNORECASE)

requirements.txt

@@ -1,5 +1,5 @@
 Babel>=1.3, <2.9
-Flask-Babel>=0.11.1,<1.1.0
+Flask-Babel>=0.11.1,<2.1.0
 Flask-Login>=0.3.2,<0.5.1
 Flask-Principal>=0.3.2,<0.5.1
 singledispatch>=3.4.0.0,<3.5.0.0
@@ -11,5 +11,5 @@ pytz>=2016.10
 requests>=2.11.1,<2.25.0
 SQLAlchemy>=1.3.0,<1.4.0
 tornado>=4.1,<6.2
-Wand>=0.4.4,<0.6.0
+Wand>=0.4.4,<0.7.0
 unidecode>=0.04.19,<1.2.0