[Minor] Fix closing tags

interface/index.html

@@ -54,7 +54,7 @@
 	<div class="d-flex flex-row order-2 order-xl-4">
 		<form class="form-inline ml-auto">
 			<div class="btn-group">
-				<button class="btn btn-outline-secondary" id="refresh" style="display: none;"><i class="fas fa-sync-alt"></i> Refresh</a>
+				<button class="btn btn-outline-secondary" id="refresh" style="display: none;"><i class="fas fa-sync-alt"></i> Refresh</button>
 				<button class="btn btn-outline-secondary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown" id="autoRefresh" title="Auto-refresh time interval">
 					<span id="countdown">--:--</span>
 				</button>
@@ -86,7 +86,7 @@
 					<a class="dropdown-item dynamic active" href="#" id="dynamic-item" data-value="3600000">1 hour</a>
 				</div>
 			</div>
-			<button class="btn btn-outline-secondary ml-2" id="disconnect"><i class="fas fa-power-off"></i> Disconnect</a>
+			<button class="btn btn-outline-secondary ml-2" id="disconnect"><i class="fas fa-power-off"></i> Disconnect</button>
 		</form>
 		<button class="navbar-toggler ml-2" type="button" data-toggle="collapse" data-target=".navbar-collapse">
 			<span class="navbar-toggler-icon"></span>