Fix javadoc generation script (#16)

diff --git a/deploy-javadoc.sh b/deploy-javadoc.sh
index d979c72..a58f6a0 100755
--- a/deploy-javadoc.sh
+++ b/deploy-javadoc.sh
@@ -3,9 +3,10 @@
 set -o errexit
 
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-JAVA_VERSION=`mvn --version | grep "Java version" | awk '{print $3}' | sed 's/,//' | cut -d. -f1`
 
-if [ "$JAVA_VERSION" -lt "7" ]; then
+
+JAVA_VERSION=`java -version 2>&1 | sed -n ';s/.* version "\(.*\)\.\(.*\)\..*"/\1\2/p;'`
+if [ "$JAVA_VERSION" -lt "17" ]; then
   echo "Use Java 1.7+ to generate the Javadoc."
   exit 1
 fi
@@ -46,7 +47,7 @@
 done
 
 cd jclouds
-mvn clean javadoc:aggregate -Dnotimestamp=true -DadditionalJOption=-J-Xmx512m
+mvn -Pdoc clean javadoc:aggregate -Dnotimestamp=true -DadditionalJOption=-J-Xmx512m
 
 
 if [ ! -d "site-content" ]; then