Use pkg-config to find OpenSSL

bind-9.14.4 appears to have introduced a new test for finding SSL
libraries, and it uses hard-coded paths ending in /lib.  On systems
where /usr/lib contains 32-bit libraries and /usr/lib64 contains 64-bit
libraries, it finds the incorrect 32-bit libraries.  It then adds a -L
flag to the 32-bit library directory, which produces warnings about
finding the wrong library format.  If linking with libdb, libtool
replaces -ldb with a full path to the library, using the 32-bit
directory specified with the -L flag, which causes linking to fail.

Fix by letting pkg-config find the OpenSSL library if it can.  This
skips adding the incorrect -L flag.  Leave the hard-coded (possibly
incorrect) paths alone.

Also fix both the existing pkg-config OpenSSL check, and the copy being
added here.  Apparently the test needs to search for libcrypto, not
crypto.

diff --git a/m4/ax_check_openssl.m4 b/m4/ax_check_openssl.m4
index 0000000..0000000 100644
--- a/m4/ax_check_openssl.m4
+++ b/m4/ax_check_openssl.m4
@@ -41,16 +41,26 @@ AC_DEFUN([AX_CHECK_OPENSSL], [
         [AS_HELP_STRING([--with-openssl=DIR],
             [root of the OpenSSL directory])],
         [
-	    AS_CASE([$with_openssl],
-	        [""|y|ye|yes],[ssldirs="$default_ssldirs"],
-	    	[n|no],[AC_MSG_ERROR([Invalid --with-openssl value])],
-            	[*],[ssldirs="$withval"],
-	    	[ssldirs="$default_ssldirs"]
-	    )
+            AS_CASE([$with_openssl],
+                [""|y|ye|yes],[
+                    # if pkg-config is installed and openssl has installed
+                    # a .pc file, then use that information and don't
+                    # search ssldirs
+                    PKG_CHECK_MODULES([OPENSSL], [libcrypto],
+                        [
+                            found=true
+                            ssldirs=""
+                        ],
+                        [ssldirs="$default_ssldirs"])
+                ],
+                [n|no],[AC_MSG_ERROR([Invalid --with-openssl value])],
+                [*],[ssldirs="$withval"],
+                [ssldirs="$default_ssldirs"]
+            )
         ], [
             # if pkg-config is installed and openssl has installed a .pc file,
             # then use that information and don't search ssldirs
-	    PKG_CHECK_MODULES([OPENSSL], [crypto],
+	    PKG_CHECK_MODULES([OPENSSL], [libcrypto],
  	        [found=true],
 	    	[ssldirs="$default_ssldirs"])