ui-shared: don't print header <img/> if there isn't a logo defined

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

ui-shared.c

@@ -611,6 +611,8 @@ void cgit_print_pageheader(struct cgit_context *ctx)
 
 	html("<table id='header'>\n");
 	html("<tr>\n");
+
+	if (ctx->cfg.logo && ctx->cfg.logo[0] != 0) {
 		html("<td class='logo' rowspan='2'><a href='");
 		if (ctx->cfg.logo_link)
 			html_attr(ctx->cfg.logo_link);
@@ -619,6 +621,7 @@ void cgit_print_pageheader(struct cgit_context *ctx)
 		html("'><img src='");
 		html_attr(ctx->cfg.logo);
 		html("' alt='cgit logo'/></a></td>\n");
+	}
 
 	html("<td class='main'>");
 	if (ctx->repo) {