update select values

smp-angular/src/app/common/panels/certificate-panel/certificate-panel.component.html

 <div id="certificate-panel" class="mat-elevation-z2">
   <h3>Selected certificate data</h3>
-  <mat-form-field *ngIf="certificate?.invalidReason">
-    <mat-label>Error message</mat-label>
-    <input matInput placeholder="Error message"
-           [value]="certificate?.invalidReason"
-           readonly>
-  </mat-form-field>
   <div style="display: flex;flex-direction: row;flex:1 1">
     <mat-form-field *ngIf="!!this.certificate?.publicKeyType"  style="flex:1 1">
       <mat-label>Public key type</mat-label>

smp-angular/src/app/system-settings/admin-domain/domain-sml-panel/domain-sml-integration-panel.component.html

@@ -71,15 +71,15 @@
     <mat-form-field style="width:100%"
                     matTooltip="Client Certificate used for SML authentication. The SML Client-Cert http Header is also generated from the certificate">
       <mat-label>SML Client Certificate Alias</mat-label>
-      <mat-select
+      <select matNativeControl
         formControlName="smlClientKeyAlias"
         id="smlClientKeyAlias_id">
-        <mat-option [value]="''">Choose certificate for signing soap response</mat-option>
-        <mat-option *ngFor="let cert of keystoreCertificates" [value]="cert.alias">
+        <option [value]="''">Choose certificate for signing soap response</option>
+        <option *ngFor="let cert of keystoreCertificates" [value]="cert.alias">
           {{cert.alias}} ({{cert.certificateId}})
-        </mat-option>
+        </option>
 
-      </mat-select>
+      </select>
     </mat-form-field>
 
     <mat-slide-toggle style="width:100%"