Don't force oh-my-zsh if it exists.

install.sh

@@ -41,6 +41,9 @@ echo "Installing vim."
 confirmAndLink $DIR/vim/vimrc $HOME/.vimrc
 confirmAndLink $DIR/vim $HOME/.vim
 
+which zsh
+if which zsh
+then
 	echo "Installing zsh"
 	
 	if [ ! -e $HOME/.oh-my-zsh ]
@@ -52,3 +55,4 @@ else
 	fi
 	
 	echo "Installation finished."
+fi