Fix undefined behaviour when loading non-existant credentials (#4674)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Dev: Added tools to help debug image GC. (#4578)
 - Dev: Removed duplicate license when having plugins enabled. (#4665)
 - Dev: Replace our QObjectRef class with Qt's QPointer class. (#4666)
+- Dev: Fixed undefined behavior when loading non-existant credentials. (#4673)
 
 ## 2.4.4
 

src/common/Credentials.cpp

@@ -197,9 +197,9 @@ void Credentials::get(const QString &provider, const QString &name_,
     }
     else
     {
-        auto &instance = insecureInstance();
+        const auto &instance = insecureInstance();
 
-        onLoaded(instance.object().find(name).value().toString());
+        onLoaded(instance[name].toString());
     }
 }