fix indentation in output of selftest.c
diff --git a/library/rsa.c b/library/rsa.c
index a6cc19b..79f86c3 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -1688,7 +1688,7 @@
 
 #if defined(MBEDTLS_SHA1_C)
     if( verbose != 0 )
-        mbedtls_printf( "PKCS#1 data sign  : " );
+        mbedtls_printf( "  PKCS#1 data sign  : " );
 
     mbedtls_sha1( rsa_plaintext, PT_LEN, sha1sum );