MINOR: Specify keyalg RSA for SSL key generation

Author: Sriharsha Chintalapani <harsha@hortonworks.com>

Reviewers: Ismael Juma <ismael@juma.me.uk>

Closes #1416 from harshach/ssl-doc-fix

docs/security.html

@@ -93,7 +93,7 @@ Apache Kafka allows clients to connect over SSL. By default SSL is disabled but
             <pre>
         #!/bin/bash
         #Step 1
-        keytool -keystore server.keystore.jks -alias localhost -validity 365 -genkey
+        keytool -keystore server.keystore.jks -alias localhost -validity 365 -keyalg RSA -genkey
         #Step 2
         openssl req -new -x509 -keyout ca-key -out ca-cert -days 365
         keytool -keystore server.truststore.jks -alias CARoot -import -file ca-cert