lib: improve error formatting for Python symlink

Logging the entire error object shows the stack twice,
and all the other information is contained in the stack.

It also messes with the order of what is logged.

Rather than logging a bunch of redundant information in a messy way,
we can log only the stack. Logging it in a separate log.warn()
also gets rid of an extra space character at the beginning of the line.

Author: DeeDeeG

lib/configure.js

@@ -97,11 +97,13 @@ function configure (gyp, argv, callback) {
 
     fs.unlink(symlinkDestination, function (err) {
       if (err && err.code !== 'ENOENT') {
-        log.warn('python symlink', 'error when attempting to remove existing symlink\n', err)
+        log.warn('python symlink', 'error when attempting to remove existing symlink')
+        log.warn('python symlink', err.stack)
       }
       fs.symlink(python, symlinkDestination, function (err) {
         if (err) {
-          log.warn('python symlink', 'error when attempting to create Python symlink\n', err)
+          log.warn('python symlink', 'error when attempting to create Python symlink')
+          log.warn('python symlink', err.stack)
         }
       })
     })