Fix broken image src in safe.dd

Author: wilzbach

articles/safed.dd

@@ -12,7 +12,7 @@ $(D_S SafeD—The Safe Subset of D,
         I've seen some very good programmers move away from C++ in favor of languages like Java or C#. Being a hard-core C++ programmer myself, I wondered why anyone would want to switch to a less powerful and less efficient language. Mind you, I could understand why a newcomer would opt for a simpler, flatter-learning-curve language but, once somebody invested the time and effort to become proficient in C++, why in the world would they want to abandon it?
         )
 
-<img src="images/dman-rain.jpg" border=0 alt="D-man in rain" style="float:right" alt="D Style" height=200>
+<img src="$(ROOT_DIR)images/dman-rain.jpg" border=0 alt="D-man in rain" style="float:right" alt="D Style" height=200>
 
         $(P
         The universal reason I've heard from the turncoats was $(DOUBLEQUOTE productivity.) The consensus seems to be that programmers are more productive using Java, C#, Ruby, or Python than they are using C++.