fix github issue and null email issue

Author: Thomasr

server/api-service/lowcoder-domain/src/main/java/org/lowcoder/domain/user/service/UserServiceImpl.java

@@ -113,6 +113,7 @@ public Mono<User> findByName(String rawUuid) {
     }
 
     public Mono<User> findByEmailDeep(String email) {
+        if(StringUtils.isEmpty(email)) return Mono.empty();
         return repository.findByEmailOrConnections_Email(email, email).next();
     }
 

server/api-service/lowcoder-server/src/main/java/org/lowcoder/api/authentication/request/oauth2/Oauth2AuthRequestFactory.java

@@ -43,7 +43,6 @@ yield new GenericAuthRequest(Oauth2GenericAuthConfig.builder()
                         .enableRegister(config.isEnableRegister())
                         .enable(config.isEnable())
                         .scope("read:email read:user")
-                        .userCanSelectAccounts(true)
                         .sourceMappings(sourceMappings)
                         .clientSecret(config.getClientSecret())
                         .clientId(config.getClientId())