plugin update

plugin/repo.xml

@@ -1,7 +1,7 @@
 <?xml version='1.0' standalone='yes'?>
 <extensions>
   <plugins>
-    <plugin version="0.20" name="SqueezeESP32" minTarget="7.5" maxTarget="*">
+    <plugin version="0.21" name="SqueezeESP32" minTarget="7.5" maxTarget="*">
       <link>https://github.com/sle118/squeezelite-esp32</link>
       <creator>Philippe</creator>
       <sha>f1955a3c930a0c1809a1d2dac85970905c9b68a0</sha>