don't deref NULL. Found by Klockwork (www.klocwork.com)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@8468 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_utils.c

@@ -568,12 +568,16 @@ SWITCH_DECLARE(char *) switch_strip_spaces(const char *str)
 	const char *sp = str;
 	char *p, *s = NULL;
 	
-	while(sp && *sp && *sp == ' ') {
+	if (!sp) return NULL;
+
+	while(*sp == ' ') {
 		sp++;
 	}
 	
 	s = strdup(sp);
 
+	if (!s) return NULL;
+
 	p = s + (strlen(s) - 1);
 
 	while(*p == ' ') {