fix(module:calendar): use correct classNames (#1118)

Author: trotyl

Diff for: components/calendar/nz-calendar-header.component.html

@@ -1,9 +1,9 @@
-<nz-select class="ant-fullcalendar--year-select" [nzSize]="size"
+<nz-select class="ant-fullcalendar-year-select" [nzSize]="size"
            [ngModel]="activeYear" (ngModelChange)="yearChange.emit($event)">
   <nz-option *ngFor="let year of years" [nzLabel]="year.label" [nzValue]="year.value"></nz-option>
 </nz-select>
 
-<nz-select *ngIf="mode === 'month'" class="ant-fullcalendar--year-select" [nzSize]="size" 
+<nz-select *ngIf="mode === 'month'" class="ant-fullcalendar-month-select" [nzSize]="size" 
            [ngModel]="activeMonth" (ngModelChange)="monthChange.emit($event)">
   <nz-option *ngFor="let month of months" [nzLabel]="month.label" [nzValue]="month.value"></nz-option>
 </nz-select>