[修改]创建用户时放开对用户名的限制

src/app/ui/usermanagement/createUser.html

@@ -4,12 +4,12 @@
 
     <div mat-dialog-content>
         <mat-form-field>
-          <input type="text" id="name" matInput pattern="^[a-zA-Z][a-zA-Z0-9_]{4,19}$"
+          <input type="text" id="name" matInput 
           required ngModel name="name" #name="ngModel" placeholder="登录账号">
         </mat-form-field>
-        <div *ngIf="name.invalid && (name.dirty || name.touched)" class="alert-danger">
+        <!-- <div *ngIf="name.invalid && (name.dirty || name.touched)" class="alert-danger">
           <div *ngIf="name.errors.pattern">登录名格式为字母开头,5-18位</div>
-        </div>
+        </div> -->
     </div>
 
     <div mat-dialog-content>