remove branch condition that could never be false

fuzzer gets 100% branch coverage now, no crashes/hangs

hmmlib2/hmmlib.h

@@ -599,7 +599,7 @@ static size_t _hmml_parse_text(struct _hmml_parser* p, HMML_Annotation* anno)
     }
 
     // trim trailing whitespace
-    while(out > text_mem && out[-1] && (uint8_t)(out[-1]) <= ' ') {
+    while(out > text_mem && (uint8_t)(out[-1]) <= ' ') {
         out[-1] = '\0';
         --out;
     }