Add spaces to pattern of session-id input field

src/app/components/shared/room-join/room-join.component.html

@@ -2,7 +2,7 @@
 <form (ngSubmit)="joinRoom(roomId.value)">
   <div fxLayout="row" fxLayoutAlign="center" fxLayoutGap="10px">
     <mat-form-field>
-      <input matInput #roomId type="text" pattern="[0-9]*" inputmode="numeric" min="00000000" max="99999999"
+      <input matInput #roomId type="text" pattern="[0-9 ]*" inputmode="numeric" min="00000000" max="99999999"
              onkeydown="if(this.value.length - (this.value.split(' ').length -1) === 8 && event.keyCode != 8) return false;
                         if(this.value.length === 4 && event.keyCode != 8) this.value = this.value + ' ';"
                         placeholder="Session-Id" [formControl]="roomFormControl" [errorStateMatcher]="matcher"/>