lib: update exports file with new API

Resolves: authselect#369
(cherry picked from commit 98b2cb9)

Author: pbrezina

src/lib/authselect.exports

@@ -86,3 +86,12 @@ AUTHSELECT_1.6.0 {
 
         authselect_feature_enabled;
 } AUTHSELECT_1.2.3;
+
+AUTHSELECT_1.7.0 {
+
+    # public functions
+    global:
+
+        authselect_files_switchableauth;
+        authselect_path_switchableauth;
+} AUTHSELECT_1.6.0;