Filtering issues by label in a specific milestone is not possible

[sv-calin]

Url: https://webcompat.com/issues

Environment:
Operating system: Windows 10
Firefox version: Nightly 104.0a1 (2022-07-17) (64-bit)

Steps to reproduce:

1. Go to https://webcompat.com/issues
2. Click on any milestone in order to select it
3. Type any label in the search bar (eg. "label:engine-gecko")
4. Press "Enter"
5. Observe the result

Expected Behavior:
Filtering issues by label in a specific milestone is possible.

Actual Behavior:
Filtering issues by label in a specific milestone is not possible, the label returns issues across all the milestones. The milestone is deselected.

Notes:

1. Video provided https://gifyu.com/image/SNpZ6
2. Reproducible on Chrome as well
3. Selecting a different milestone and applying the same label won't do anything (works if you apply a different label): https://gifyu.com/image/SNpaB

Watchers:
@softvision-oana-arbuzov
@softvision-raul-bucata
@ClintNase

[karlcow]

It goes from
https://webcompat.com/issues?page=1&per_page=50&state=open&stage=needsdiagnosis&sort=created&direction=desc

to

https://webcompat.com/issues?page=1&per_page=50&state=open&stage=all&sort=created&direction=desc&q=label%3Aengine-gecko

stage parameter switched from needsdiagnosis to all

[karlcow]

webcompat.com/webcompat/static/js/lib/models/issue.js

Lines 154 to 167 in 67f2831

	model: issueModel,
	/* the url property is set in issueList.IssueView#fetchAndRenderIssues */
	initialize: function (options) {
	// set defaults
	this.params = (options && options.params) || {
	page: 1,
	per_page: 50,
	state: "open",
	stage: "all",
	sort: "created",
	direction: "desc",
	};
	this.path = (options && options.path) || "/api/issues";
	},