adjusted pathvariable annotation

Author: Wei-HaiMing

src/main/java/com/grouptwelve/grouptwelveBE/controller/Controller.java

@@ -53,7 +53,7 @@ public List<User> getAllUsers() {
     }
 
     @GetMapping("/users/email/{email}") // GET 3
-    public User getUsersByEmail(@PathVariable String email) {
+    public User getUsersByEmail(@PathVariable("email") String email) {
         return userRepository.findByEmail(email);
     }