Add symlink for backwards compatibility

The native code has to run with an old verison of Magisk Manager,
add this back so things will work properly.

native/jni/core/bootstages.cpp

@@ -351,6 +351,9 @@ static bool magisk_env() {
 	xmkdir(BBPATH, 0755);
 	xmkdir(MODULEMNT, 0755);
 
+	// Backwards compatibility for old Magisk Manager
+	xsymlink("./modules", MAGISKTMP "/img");
+
 	// Directories in /data/adb
 	xmkdir(DATABIN, 0755);
 	xmkdir(MODULEROOT, 0755);