bootstrap: Fix syntax error for Node older than 10

We don't actually support Node older than 10 for successfully
bootstrapping an Atom build, but we should support older Node in the
system requirements checker script so that we can print useful errors,
like ones to tell the user their system's copy of Node is too old!

(It was me that introduced this Node 10.0.0 or above-only syntax
about a year ago... My mistake. It's as good a time as any to fix it!)

Author: DeeDeeG

script/lib/verify-machine-requirements.js

@@ -94,7 +94,7 @@ function verifyPython() {
           env: process.env,
           stdio: ['ignore', 'pipe', 'ignore']
         });
-      } catch {}
+      } catch (e) {}
 
       if (stdout) {
         if (stdout.indexOf('+') !== -1)