Reimplemented API Provider

To try to fix NullPointerException on mApi reported in Play Store

app/build.gradle

@@ -18,12 +18,12 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 31
 
     defaultConfig {
         applicationId "it.danieleverducci.nextcloudmaps"
         minSdkVersion 23
-        targetSdkVersion 30
+        targetSdkVersion 31
         versionCode 6
         versionName "0.3.4"
 
@@ -54,7 +54,7 @@ repositories {
 dependencies {
     implementation fileTree(dir: "libs", include: ["*.jar"])
 
-    implementation 'com.android.support:design:30.0.1'
+    implementation 'com.android.support:design:31.0.0'
     implementation 'androidx.appcompat:appcompat:1.3.1'
     implementation 'androidx.recyclerview:recyclerview:1.2.1'
     implementation "androidx.cardview:cardview:1.0.0"
@@ -70,7 +70,7 @@ dependencies {
     implementation 'com.squareup.retrofit2:converter-gson:2.6.1'
 
     // Nextcloud SSO
-    implementation "com.github.nextcloud:Android-SingleSignOn:0.5.6"
+    implementation "com.github.nextcloud:Android-SingleSignOn:0.6.1"
 
     // OSMDroid
     implementation 'org.osmdroid:osmdroid-android:6.1.10'