Fix alembic prod & dev URLs

backend/alembic.dev.ini

@@ -6,7 +6,7 @@ prepend_sys_path = .
 
 version_path_separator = os
 
-sqlalchemy.url = sqlite:////mnt/data/languagelab/db.dev.sqlite3
+sqlalchemy.url = sqlite:////mnt/data/languagelab/backend/db.dev.sqlite3
 
 [post_write_hooks]
 hooks = black

backend/alembic.prod.ini

@@ -6,7 +6,7 @@ prepend_sys_path = .
 
 version_path_separator = os
 
-sqlalchemy.url = sqlite:////mnt/data/languagelab/db.sqlite3
+sqlalchemy.url = sqlite:////mnt/data/languagelab/backend/db.sqlite3
 
 [post_write_hooks]
 hooks = black