Add user role name with slash "/"

[crazydavidoff]

If add user role name with "/" you cannot delete it.

Expected Behavior

Current Behavior

There was an error fetching a resource: cannot GET http://172.16.20.58:9000/api/roles/%20Stream/Dashboard%20Editor/members (404). Additional information: HTTP 404 Not Found

t @ plugin.org.graylog.plugins.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:1
plugin.org.graylog.plugins.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:55 Unhandled rejection Error: cannot GET http://172.16.20.58:9000/api/roles/%20Stream/Dashboard%20Editor/members (404)
    at new t (http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…s.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:1:2770)
    at http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…s.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:1:4196
From previous event:
    at h.r.then (http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…ipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:257:20641)
    at e.value (http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…s.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:1:3714)
    at i (http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…s.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:1:1711)
    at s (http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…s.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:1:1782)
    at Object.getMembers (http://example.com/assets/plugin/org.graylog.plugins.pipelineprocessor.Pr…ipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:143:20338)
    at n._deleteRole (http://example.com/assets/38.38.037df0c3d824b82fe316.js:1:9159)
    at onClick (http://example.com/assets/38.38.037df0c3d824b82fe316.js:1:7245)
    at Object.r.invokeGuardedCallback (http://example.com/assets/vendor.js:29:11002)
    at i (http://example.com/assets/vendor.js:33:26673)
    at Object.s [as executeDispatchesInOrder] (http://example.com/assets/vendor.js:33:26920)
    at f (http://example.com/assets/vendor.js:8:11906)
    at M (http://example.com/assets/vendor.js:8:12032)
    at Array.forEach (native)
    at n (http://example.com/assets/vendor.js:29:18772)
    at Object.processEventQueue (http://example.com/assets/vendor.js:8:13329)
    at o (http://example.com/assets/vendor.js:35:7775)
    at Object.handleTopLevel [as _handleTopLevel] (http://example.com/assets/vendor.js:35:7880)
    at i (http://example.com/assets/vendor.js:35:8329)
    at a (http://example.com/assets/vendor.js:35:8143)
    at o.perform (http://example.com/assets/vendor.js:8:25971)
    at Object.batchedUpdates (http://example.com/assets/vendor.js:29:4842)
    at Object.a [as batchedUpdates] (http://example.com/assets/vendor.js:7:19906)
    at dispatchEvent (http://example.com/assets/vendor.js:35:9220)
O @ plugin.org.graylog.plugins.pipelineprocessor.PipelineProcessorPlugin.3256fc68b6ac83634199.js:55

Possible Solution

Steps to Reproduce (for bugs)

Context

Your Environment

• Graylog Version:2.2.1
• Elasticsearch Version: 2.4.4
• MongoDB Version: 3.4
• Operating System:
• Browser version: Chrome