Debugger: Do not soft-assert on missing tool chain

Not having a tool chain is actually allowed, so do not soft-assert
for that.

Change-Id: Ia913fa271a1f1e299451e9fabd4ed6bcfb32f043
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/debugger/debuggerkitinformation.cpp

@@ -59,7 +59,8 @@ DebuggerKitInformation::DebuggerKitInformation()
 QVariant DebuggerKitInformation::defaultValue(Kit *k) const
 {
     ToolChain *tc = ToolChainKitInformation::toolChain(k);
-    QTC_ASSERT(tc, return QVariant());
+    if (!tc)
+        return QVariant();
 
     const Abi toolChainAbi = tc->targetAbi();
     foreach (const DebuggerItem &item, DebuggerItemManager::debuggers())