Merge pull request #1461 from Valiuapp/develop

Fix-[Sandbox] If the child process is killed, remove it from the pool.

lib/process/sandbox.js

@@ -52,7 +52,7 @@ module.exports = function(processFile, childPool) {
         child.removeListener('message', msgHandler);
         child.removeListener('exit', exitHandler);
 
-        if (child.exitCode !== null) {
+        if (child.exitCode !== null || /SIG.*/.test(child.signalCode)) {
           childPool.remove(child);
         } else {
           childPool.release(child);