fix appinfo parsing when a single localized option is provided

[icewind1991]

See #8223

[MorrisJobke]

Tested and works 👍

[MorrisJobke]

Fixes this issue:

{
    "reqId": "pzYTbLf31SIos81QcAFn",
    "level": 3,
    "time": "2018-04-12T11:46:26+00:00",
    "remoteAddr": "172.20.0.1",
    "user": "admin",
    "app": "PHP",
    "method": "GET",
    "url": "/index.php/settings/apps/list?category=updates",
    "message": "Undefined index: @value at /var/www/html/lib/private/legacy/app.php#1019",
    "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.1 Safari/605.1.15",
    "version": "14.0.0.2"
}

[MorrisJobke]

Rebased to trigger stuck CI.

[codecov]

Codecov Report

Merging #9159 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master    #9159      +/-   ##
============================================
+ Coverage      51.9%   51.92%   +0.02%     
- Complexity    25359    25360       +1     
============================================
  Files          1606     1606              
  Lines         95310    95312       +2     
  Branches       1394     1394              
============================================
+ Hits          49470    49493      +23     
+ Misses        45840    45819      -21

Impacted Files	Coverage Δ	Complexity Δ
lib/private/legacy/app.php	62.63% <100%> (+3.76%)	196 <0> (+1)	⬆️
core/js/js.js	65.88% <0%> (+0.55%)	0% <0%> (ø)	⬇️

[nickvergessen]

Should backport

[MorrisJobke]

stable13 #9233