fix(wallet): hide zero channel balance

If the total channel balance is zero, do not show the channel balance at
the top of the network view as the zero doesn't convey any useful
information and looks strange.

app/components/Contacts/Network/Network.js

@@ -173,12 +173,14 @@ class Network extends Component {
               <FormattedMessage {...messages.title} />
             </h2>
             <span className={styles.channelAmount}>
-              <Value
+              {Boolean(balance.channelBalance) && (
-                value={balance.channelBalance}
+                <Value
-                currency={ticker.currency}
+                  value={balance.channelBalance}
-                currentTicker={currentTicker}
+                  currency={ticker.currency}
-                fiatTicker={ticker.fiatTicker}
+                  currentTicker={currentTicker}
-              />
+                  fiatTicker={ticker.fiatTicker}
+                />
+              )}
               {Boolean(fiatAmount) && (
                 <span>
                   {'≈ '}