[FAB-9438] Fix protos compilation perm denied

The protos compilation needs to skip the .build directory.  It used to
exclude the 'build' directory, but was not updated when the dir was
renamed.  This CR fixes the exclusion.

Change-Id: I52b2018c00dddd42e4925e772fea5127335f1337
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

scripts/compile_protos.sh

@@ -21,7 +21,7 @@ PROTO_ROOT_DIRS="$(dirname $PROTO_ROOT_FILES)"
 ROOTLESS_PROTO_FILES="$(find $PWD \
                              $(for dir in $PROTO_ROOT_DIRS ; do echo "-path $dir -prune -o " ; done) \
                              -path $PWD/vendor -prune -o \
-                             -path $PWD/build -prune -o \
+                             -path $PWD/.build -prune -o \
                              -path $PWD/core/chaincode/shim/java -prune -o \
                              -name "*.proto" -exec readlink -f {} \;)"
 ROOTLESS_PROTO_DIRS="$(dirname $ROOTLESS_PROTO_FILES | sort | uniq)"