docs(README): fix light svg path

Co-authored-by: Ege Korkan <egekorkan@gmail.com>

Author: relu91

README.md

@@ -1,6 +1,6 @@
 <picture>
   <source media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/eclipse-thingweb/thingweb/master/brand/logos/node-wot_for_dark_bg.svg">
-  <source media="(prefers-color-scheme: light)" srcset="https://raw.githubusercontent.com/eclipse-thingweb/thingweb/master/brand/logos/node-wot.svg.svg">
+  <source media="(prefers-color-scheme: light)" srcset="https://raw.githubusercontent.com/eclipse-thingweb/thingweb/master/brand/logos/node-wot.svg">
   <img title="ThingWeb node-wot" alt="Thingweb node-wot logo" src="https://raw.githubusercontent.com/eclipse-thingweb/thingweb/master/brand/logos/node-wot.svg" width="300">
 </picture>