Adding missing error output on /blocks page.

frontend/src/app/components/latest-blocks/latest-blocks.component.ts

@@ -15,7 +15,7 @@ import { map } from 'rxjs/operators';
 })
 export class LatestBlocksComponent implements OnInit, OnDestroy {
   network$: Observable<string>;
-
+  error: any;
   blocks: any[] = [];
   blockSubscription: Subscription;
   isLoading = true;
@@ -86,6 +86,7 @@ export class LatestBlocksComponent implements OnInit, OnDestroy {
       .subscribe((blocks) => {
         this.blocks = blocks;
         this.isLoading = false;
+        this.error = undefined;
 
         this.latestBlockHeight = blocks[0].height;
 
@@ -95,6 +96,12 @@ export class LatestBlocksComponent implements OnInit, OnDestroy {
           this.loadMore(chunks);
         }
         this.cd.markForCheck();
+      },
+      (error) => {
+        console.log(error);
+        this.error = error;
+        this.isLoading = false;
+        this.cd.markForCheck();
       });
   }
 
@@ -107,12 +114,19 @@ export class LatestBlocksComponent implements OnInit, OnDestroy {
       .subscribe((blocks) => {
         this.blocks = this.blocks.concat(blocks);
         this.isLoading = false;
+        this.error = undefined;
 
         const chunksLeft = chunks - 1;
         if (chunksLeft > 0) {
           this.loadMore(chunksLeft);
         }
         this.cd.markForCheck();
+      },
+      (error) => {
+        console.log(error);
+        this.error = error;
+        this.isLoading = false;
+        this.cd.markForCheck();
       });
   }