prevent double res.send/json if error occurs in profile image upload

src/routes/user.js

@@ -176,8 +176,7 @@ var fs = require('fs'),
 					user.setUserField(uid, 'picture', imageUrl);
 
 					if (convertToPNG && extension !== '.png') {
-						im.convert([uploadPath, 'png:-'],
-							function(err, stdout){
+						im.convert([uploadPath, 'png:-'], function(err, stdout) {
 							if (err) {
 								winston.err(err);
 								res.send({
@@ -187,12 +186,15 @@ var fs = require('fs'),
 							}
 
 							fs.writeFileSync(uploadPath, stdout, 'binary');
-							});
-					}
-
 							res.json({
 								path: imageUrl
 							});
+						});
+					} else {
+						res.json({
+							path: imageUrl
+						});
+					}
 				}
 
 				if(extension === '.gif') {