Escape \ in env.py

https://github.com/alexbelgium/hassio-addons/issues/1352

.templates/00-global_var.sh

@@ -68,7 +68,11 @@ for KEYS in "${arr[@]}"; do
         # export to python
         if command -v "python3" &>/dev/null && ; then
             [ ! -f /env.py ] && echo "import os" > /env.py
-            echo "os.environ['${KEYS}'] = '${VALUE//[\"\'\\]/}'" >> /env.py
+            # Escape \
+            VALUEPY="${VALUEPY//\\/\\\\}"
+            # Avoid " and '
+            VALUEPY="${VALUE//[\"\']/}"
+            echo "os.environ['${KEYS}'] = '$VALUEPY'" >> /env.py
             python3 /env.py
         fi
         # set .env