1) Fix potential NPE in com.clickhouse.client.api.ssl.context.FromKeyStoreSslContextStrategy#createSSLContext

2) Correct PEM dashes

Author: sbushmelev

client-v2/src/main/java/com/clickhouse/client/api/ssl/context/FromKeyStoreSslContextStrategy.java

@@ -37,7 +37,7 @@ public SSLContext createSSLContext() {
         try (InputStream in = ClickHouseUtils.getFileInputStream(trustStorePath)) {
             SSLContext ctx = SSLContext.getInstance((String) config.get(ClientConfigProperties.SSL_PROTOCOL.getKey()));
             KeyStore myTrustStore = KeyStore.getInstance(keyStoreType);
-            myTrustStore.load(in, truststorePassword.toCharArray());
+            myTrustStore.load(in, truststorePassword != null ? truststorePassword.toCharArray() : null);
             TrustManagerFactory factory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
             factory.init(myTrustStore);
             ctx.init(null, factory.getTrustManagers(), new SecureRandom());

client-v2/src/main/java/com/clickhouse/client/api/ssl/keystore/DefaultCertificateKeyStoreManager.java

@@ -22,9 +22,9 @@
 
 public final class DefaultCertificateKeyStoreManager implements CertificateKeyStoreManager {
 
-    private static final String PEM_HEADER_PREFIX = "---BEGIN ";
-    private static final String PEM_HEADER_SUFFIX = " PRIVATE KEY---";
-    private static final String PEM_FOOTER_PREFIX = "---END ";
+    private static final String PEM_HEADER_PREFIX = "-----BEGIN ";
+    private static final String PEM_HEADER_SUFFIX = " PRIVATE KEY-----";
+    private static final String PEM_FOOTER_PREFIX = "-----END ";
 
     private final Map<String, Object> config;