Update requirements_opt.txt

Japhiolite · Japhiolite · commit 2461d3f1f6aa · 2022-08-02T10:42:22.000+02:00
diff --git a/requirements_opt.txt b/requirements_opt.txt
@@ -1,6 +1,6 @@
 openpyxl
 
-welly
+welly == 0.4.8
 
 # There is an open PR for striplog
 git+https://github.com/Leguark/striplog.git
