fix(spawnify) _set setEncoding when child is null

Author: coderaiser

lib/spawnify.js

@@ -128,13 +128,13 @@
             break;
         }
 
-        child.stderr.setEncoding('utf-8');
-        child.stdout.setEncoding('utf-8');
-        child.stdin.setEncoding('utf-8');
-        
         if (error) {
             this._emit('error', newLine(error));
         } else {
+            child.stderr.setEncoding('utf-8');
+            child.stdout.setEncoding('utf-8');
+            child.stdin.setEncoding('utf-8');
+            
             this._setListeners(child);
 
             this.on('kill', function(code) {