[sprixels] plug two memory leaks

src/lib/internal.h

@@ -1239,6 +1239,9 @@ plane_blit_sixel(sprixel* spx, char* s, int bytes, int rows, int cols,
   }
   if(n){
 //fprintf(stderr, "TACACHE WAS: %p NOW: %p size: %d/%d\n", n->tacache, tacache, rows, cols);
+    if(n->tacache != tacache){
+      free(n->tacache);
+    }
     n->tacache = tacache;
     n->tacachey = rows;
     n->tacachex = cols;

src/lib/sprite.c

@@ -100,6 +100,7 @@ sprixel* sprixel_alloc(ncplane* n, ncvisual* ncv, int dimy, int dimx){
 int sprixel_load(sprixel* spx, char* s, int bytes, int placey, int placex,
                  int pixy, int pixx, int parse_start){
   assert(spx->n);
+  free(spx->glyph);
   spx->glyph = s;
   spx->glyphlen = bytes;
   spx->invalidated = SPRIXEL_INVALIDATED;