Use own okHttpClient for coil ImageLoader

This change will use the own okHttpClient which also contains the trusted key.

It will avoid the SSLHandshakeException:

E/RealImageLoader: javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
        at com.google.android.gms.org.conscrypt.ConscryptFileDescriptorSocket.startHandshake(:com.google.android.gms@224915028@22.49.15 (100400-499306216):25)
        at okhttp3.internal.connection.RealConnection.connectTls(RealConnection.kt:379)
        at okhttp3.internal.connection.RealConnection.establishProtocol(RealConnection.kt:337)

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/application/NextcloudTalkApplication.kt

@@ -255,6 +255,8 @@ class NextcloudTalkApplication : MultiDexApplication(), LifecycleObserver {
             imageLoaderBuilder.logger(DebugLogger())
         }
 
+        imageLoaderBuilder.okHttpClient(okHttpClient)
+
         return imageLoaderBuilder.build()
     }