Update snapcraft.yaml

Adding serial-port plug to snap to be able to work with mbus.

snap/snapcraft.yaml

@@ -86,6 +86,7 @@ apps:
       - network
       - network-bind
       - raw-usb
+      - serial-port
       - system-observe
 
 layout:
@@ -127,4 +128,4 @@ layout:
   /usr/lib/$CRAFT_ARCH_TRIPLET/liblber-2.5.so.0:
     symlink: $SNAP/usr/lib/$CRAFT_ARCH_TRIPLET/liblber-2.5.so.0
   /usr/lib/$CRAFT_ARCH_TRIPLET/libsasl2.so.2:
-    symlink: $SNAP/usr/lib/$CRAFT_ARCH_TRIPLET/libsasl2.so.2
+    symlink: $SNAP/usr/lib/$CRAFT_ARCH_TRIPLET/libsasl2.so.2