Platform: fixed assertions.

src/Platform/AbstractXApplication.cpp

@@ -51,7 +51,7 @@ void AbstractXApplication::createContext(const Configuration& configuration) {
 }
 
 bool AbstractXApplication::tryCreateContext(const Configuration& configuration) {
-    CORRADE_ASSERT(!c, "AbstractXApplication::tryCreateContext(): context already created", );
+    CORRADE_ASSERT(!c, "AbstractXApplication::tryCreateContext(): context already created", false);
 
     viewportSize = configuration.size();
 

src/Platform/WindowlessGlxApplication.cpp

@@ -54,7 +54,7 @@ void WindowlessGlxApplication::createContext(const Configuration& configuration)
 }
 
 bool WindowlessGlxApplication::tryCreateContext(const Configuration&) {
-    CORRADE_ASSERT(!c, "Platform::WindowlessGlxApplication::tryCreateContext(): context already created", );
+    CORRADE_ASSERT(!c, "Platform::WindowlessGlxApplication::tryCreateContext(): context already created", false);
 
     display = XOpenDisplay(nullptr);