fix(signup): validate check_type in duplicate duplicate_check endpoint#3956

KanhaiyaPandey wants to merge 1 commit intoprocessing:developprocessing/p5.js-web-editor:developfrom

KanhaiyaPandey:fix/duplicate-check-validate-check-typeKanhaiyaPandey/p5.js-web-editor:fix/duplicate-check-validate-check-typeCopy head branch name to clipboard