delete email unique index

Author: vkarpov15

src/db/user.js

@@ -26,6 +26,5 @@ const userSchema = new mongoose.Schema({
 }, { timestamps: true, id: false });
 
 userSchema.index({ githubUserId: 1 }, { unique: true });
-userSchema.index({ email: 1 }, { unique: true });
 
 module.exports = userSchema;