protobufjs-cli: OS Command Injection

protobufjs-cli is the command line add-on for protobuf.js. Prior to 1.2.1 and 2.0.2, pbts invoked JSDoc by building a shell command string from input file paths and executing it through child_process.exec. File paths containing shell metacharacters could therefore be interpreted by the shell instead of being passed to JSDoc as plain arguments. This vulnerability is fixed in 1.2.1 and 2.0.2.