Update build script for data-encoding to fix broken build (google#12980)

The unpublished v3-preview feature has been removed by
ia0/data-encoding#120. The v3 development
version will be added in a separate folder. I'll update the build script
to add the fuzzing for v3 once that's done.

projects/data-encoding/build.sh

@@ -16,7 +16,7 @@
 ################################################################################
 
 cd lib
-cargo fuzz build --features=data-encoding/v3-preview
+cargo fuzz build
 
 find $SRC/data-encoding/target/x86_64-unknown-linux-gnu/release -maxdepth 1 \
     -type f -perm -u=x -exec cp {} $OUT \;