6894461: OCSP Checker should not wrap all Exception as "Unable to send OCSP...

6894461: OCSP Checker should not wrap all Exception as "Unable to send OCSP request."(introduced by #6885667)
Reviewed-by: vinnie, xuelei

src/share/classes/sun/security/provider/certpath/OCSPChecker.java

@@ -335,10 +335,13 @@ class OCSPChecker extends PKIXCertPathChecker {
             response = OCSP.check(Collections.singletonList(certId), uri,
                 responderCert, pkixParams.getDate());
         } catch (Exception e) {
-            // Wrap all exceptions in CertPathValidatorException so that
+            if (e instanceof CertPathValidatorException) {
+                throw (CertPathValidatorException) e;
+            } else {
+                // Wrap exceptions in CertPathValidatorException so that
                 // we can fallback to CRLs, if enabled.
-            throw new CertPathValidatorException
-                ("Unable to send OCSP request", e);
+                throw new CertPathValidatorException(e);
+            }
         }
 
         RevocationStatus rs = (RevocationStatus) response.getSingleResponse(certId);