Add checking for rsync dependency

bedrock-linux-99.99.99-x86_64.sh

@@ -27,10 +27,14 @@ else
 		exit_success
 	fi
 fi
-make SKIPSIGN=true -j $(nproc) BEDROCK_VERSION="${newest_version}"
-/bedrock/libexec/busybox sh "bedrock-linux-${newest_version}-$(uname -m).sh" --force-update
-echo "Syncing to disk..."
-sync
-#echo "If there were no errors up to this point, then everything has gone smoothly. Ignore any following errors!"
-echo "Done!"
-exit_success
+if brl which rsync 2>&1 > /dev/null; then
+	make SKIPSIGN=true -j $(nproc) BEDROCK_VERSION="${newest_version}"
+	/bedrock/libexec/busybox sh "bedrock-linux-${newest_version}-$(uname -m).sh" --force-update
+	echo "Syncing to disk..."
+	sync
+	#echo "If there were no errors up to this point, then everything has gone smoothly. Ignore any following errors!"
+	echo "Done!"
+	exit_success
+else
+	abort "Rsync must be installed!"
+fi