simplify library autoconfigure
diff --git a/auto/lib/conf b/auto/lib/conf
index 6411dab..fcf2b3f 100644
--- a/auto/lib/conf
+++ b/auto/lib/conf
@@ -16,6 +16,7 @@
         have=NGX_HAVE_OPENSSL_MD5_H . auto/have
         have=NGX_OPENSSL_MD5 . auto/have
         MD5=YES
+        MD5_LIB=OpenSSL
 
     else
         . auto/lib/md5/conf
@@ -28,6 +29,7 @@
     if [ $OPENSSL != NONE -a $OPENSSL != NO ]; then
         have=NGX_HAVE_OPENSSL_SHA1_H . auto/have
         SHA1=YES
+        SHA1_LIB=OpenSSL
 
     else
         . auto/lib/sha1/conf