Logging: Revert including timestamps in stdout pattern

As per the discussion. Note that these can still be added dynamically
via the `QT_MESSAGE_PATTERN` environment variable.

This reverts commit aaadfd1.

src/util/logging.cpp

@@ -74,14 +74,11 @@ bool s_debugAssertBreak = false;
 // QT_MESSAGE_PATTERN="%{type} [{{threadname}}] %{function} %{message}"
 // TODO: Adjust the default format and messages and collect file and function info in release builds as well.
 
-const QString kTimestampPattern = QStringLiteral("%{time h:mm:ss.zzz}");
 const QString kThreadNamePattern = QStringLiteral("{{threadname}}");
-const QString kDefaultMessagePattern = kTimestampPattern +
-        QStringLiteral(" %{type} [") + kThreadNamePattern +
-        QStringLiteral("] %{message}");
+const QString kDefaultMessagePattern = QStringLiteral("%{type} [") +
+        kThreadNamePattern + QStringLiteral("] %{message}");
 
 const QString kDefaultMessagePatternColor =
-        kTimestampPattern +
         QStringLiteral(
                 " %{if-category}\033[35m %{category}:\033[35m%{endif}"
                 "%{if-debug}\033[34m%{type}%{endif}"