fixed plugin css files for relative path

src/plugins.js

@@ -2,6 +2,7 @@ var fs = require('fs'),
 	path = require('path'),
 	async = require('async'),
 	winston = require('winston'),
+	nconf = require('nconf'),
 	eventEmitter = require('events').EventEmitter,
 	db = require('./database');
 

src/routes/plugins.js

@@ -26,9 +26,12 @@ var	nconf = require('nconf'),
 
 		// Static Assets
 		app.get('/plugins/:id/*', function(req, res) {
-			var	relPath = req._parsedUrl.pathname.replace('/plugins/' + req.params.id, '');
+
+			var	relPath = req._parsedUrl.pathname.replace(nconf.get('relative_path') + '/plugins/' + req.params.id, '');
+
 			if (plugins.staticDirs[req.params.id]) {
 				var	fullPath = path.join(plugins.staticDirs[req.params.id], relPath);
+
 				fs.exists(fullPath, function(exists) {
 					if (exists) {
 						res.sendfile(fullPath, {

src/webserver.js

@@ -94,7 +94,7 @@ if(nconf.get('ssl')) {
 				}],
 				templateValues = {
 					cssSrc: meta.config['theme:src'] || nconf.get('relative_path') + '/vendor/bootstrap/css/bootstrap.min.css',
-					pluginCSS: plugins.cssFiles.map(function(file) { return { path: file + (meta.config['cache-buster'] ? '?v=' + meta.config['cache-buster'] : '') }; }),
+					pluginCSS: plugins.cssFiles.map(function(file) { return { path: '/nodebb'+file + (meta.config['cache-buster'] ? '?v=' + meta.config['cache-buster'] : '') }; }),
 					title: meta.config.title || '',
 					description: meta.config.description || '',
 					'brand:logo': meta.config['brand:logo'] || '',