clang-tidy: Override "WarningsAsErrors" from config file

If WarningsAsErrors is enabled in the config file, any issues that are
found will make Qt Creator believe that clang-tidy has failed. So we
never want this in our analyzing.

Fixes: QTCREATORBUG-23423
Change-Id: I38f15588a9a02e25e0cf2f56c176c95639b97432
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/clangtools/clangtidyclazyrunner.cpp

@@ -61,7 +61,7 @@ static QStringList tidyChecksArguments(const ClangDiagnosticConfig diagnosticCon
         return {"-config={}"};
     if (tidyMode == ClangDiagnosticConfig::TidyMode::UseCustomChecks)
         return {"-config={}", "-checks=" + diagnosticConfig.clangTidyChecks()};
-    return {};
+    return {"--warnings-as-errors=-*"};
 }
 
 static QStringList clazyChecksArguments(const ClangDiagnosticConfig diagnosticConfig)