classpath: fix typo in CLASSPATH_CONF_OPTS definition

This typo was introduced by commit
8f8c02e596e781df77b8cd7d5e7b3c33ae5e36b2 ("classpath: bump to version
0.99").

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/classpath/classpath.mk

@@ -11,7 +11,7 @@ CLASSPATH_CONF_OPTS = \
 	--disable-rpath \
 	--disable-Werror \
 	--disable-gconf-peer \
-	--disable-gjdoc
+	--disable-gjdoc \
 	--enable-tools
 
 # classpath assumes qt runs on top of X11, but we