Fix build warning.

lib/base/base.vcxproj

@@ -68,6 +68,7 @@
     <ClInclude Include="bufferedstream.h" />
     <ClInclude Include="consolelogger.h" />
     <ClInclude Include="convert.h" />
+    <ClInclude Include="debug.h" />
     <ClInclude Include="dynamicobject.h" />
     <ClInclude Include="dictionary.h" />
     <ClInclude Include="dynamictype.h" />

lib/base/base.vcxproj.filters

@@ -270,6 +270,9 @@
     <ClInclude Include="scriptvariable.h">
       <Filter>Headerdateien</Filter>
     </ClInclude>
+    <ClInclude Include="debug.h">
+      <Filter>Headerdateien</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Filter Include="Quelldateien">

lib/base/debug.h

@@ -44,7 +44,9 @@ inline int icinga_assert_fail(const char *expr, const char *file, int line)
 	fprintf(stderr, "%s:%d: assertion failed: %s\n", file, line, expr);
 	abort();
 
+#ifndef __GNUC__
 	return 0;
+#endif /* __GNUC__ */
 }
 
 #endif /* DEBUG_H */