Bump version to Mbed TLS 2.20.0
diff --git a/library/Makefile b/library/Makefile
index 6aeb95f..ca063f4 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -36,7 +36,7 @@
 endif
 endif
 
-SOEXT_CRYPTO=so.3
+SOEXT_CRYPTO=so.4
 
 # Set AR_DASH= (empty string) to use an ar implementation that does not accept
 # the - prefix for command line options (e.g. llvm-ar)