i18n: fix configuration

+ Only look for translations in valid files.

Change-Id: I350478d050118c8b5d6bd127aaeed6c3965fe05f
GitLab: #1266

.tx/config

@@ -3,6 +3,5 @@ host = https://www.transifex.com
 
 [o:savoirfairelinux:p:jami:r:jami_client_qt]
 file_filter = translations/jami_client_qt_<lang>.ts
-source_file = translations/jami_client_qt.ts
-source_lang = en
+source_file = translations/jami_client_qt_en.ts
 type        = TS

extras/scripts/update-translations.ps1

@@ -10,4 +10,4 @@ if (-not(Test-Path -Path $QtDir)) {
 $lupdate = "$QtDir\bin\lupdate.exe"
 
 $tsFileNames = Get-ChildItem -Path "$clientDir\translations" -Recurse -Include *.ts
-Invoke-Expression("$lupdate $clientDir\src -ts $tsFileNames -no-obsolete")
+Invoke-Expression("$lupdate -extensions cpp,h,qml $clientDir\src -ts $tsFileNames -no-obsolete")