parseconfig: skip a NULL check

Coverity CID 1154198. This NULL check implies that the pointer _can_ be
NULL at this point, which it can't. Thus it is dead code. It tricks
static analyzers to warn about dereferencing the pointer since the code
seems to imply it can be NULL.

src/tool_parsecfg.c

@@ -208,7 +208,7 @@ int parseconfig(const char *filename, struct GlobalConfig *global)
         }
       }
 
-      if(param && !*param) {
+      if(!*param) {
         /* do this so getparameter can check for required parameters.
            Otherwise it always thinks there's a parameter. */
         if(alloced_param)