Fix recursion loop in search bar

[natsoni]

Fixes #5247

The recursion was caused by the following:

Clicking on any item in the search results that does not match any regex, for example the future SegWit version address bc1pfeessrawgf (prior commit 7d7f9b1) would start a loop that never ends.

mempool/frontend/src/app/components/search-form/search-results/search-results.component.ts

Lines 70 to 71 in 0a11680

	clickItem(id: number) {
	this.selectedResult.emit(this.resultsFlattened[id]);

triggers

mempool/frontend/src/app/components/search-form/search-form.component.ts

Lines 240 to 242 in 0a11680

	selectedResult(result: any): void {
	if (typeof result === 'string') {
	this.search(result);

triggers (because no regex match)

mempool/frontend/src/app/components/search-form/search-form.component.ts

Lines 305 to 307 in 0a11680

	} else {
	this.searchResults.searchButtonClick();
	this.isSearching = false;

triggers

mempool/frontend/src/app/components/search-form/search-results/search-results.component.ts

Lines 38 to 40 in 0a11680

	searchButtonClick() {
	if (this.resultsFlattened[this.activeIdx]) {
	this.selectedResult.emit(this.resultsFlattened[this.activeIdx]);

...etc

---

This PR removes the line that triggers the search back when no regex matches.

[softsimon]

tested ACK @ [8c07e3c]