Fix content-type in image upload

stpkg

 #!/bin/bash
 
 # TODO:
-# Scale up, not only down
+# Scale up, not only down??
 # Fail on remove empty sticker pack dir
 # Test trusted source
+# Preview
+# Thumbnails: https://github.com/matrix-org/synapse/issues/13039 (manually upload small version of the sticker (32x32?) and uses this as thumbnail_url)
+# Store hash of source sticker in .stickerpack-hash.json to prevent pack to reupload unchanged stickers (default, can be overriden with flag)
 
 shopt -s nocasematch    # Case insensitive
 
@@ -277,8 +280,8 @@ STPKG_NO_MSG='no'
 STPKG_MAX_HEIGHT=128
 STPKG_MAX_WIDTH=256
 STPKG_GENERATE_PREVIEW="no"
-STPKG_IMAGE_TARGET_FILETYPE="png"
-STPKG_ANIMATED_TARGET_FILETYPE="gif"
+STPKG_IMAGE_TARGET_FILETYPE="image/png"
+STPKG_ANIMATED_TARGET_FILETYPE="image/gif"
 
 __do_mount() { :; }
 
@@ -664,7 +667,7 @@ process_sticker_file() {
 
     fi
 
-    # TODO: check for gifs here
+    # TODO: correctly get max width/height for animated
     DEST_WIDTH=$(file_get_width "$TEMP")
     DEST_HEIGHT=$(file_get_height "$TEMP")
 
@@ -910,8 +913,8 @@ __do_command() {
             STPKG_MAX_HEIGHT=${STPKG_MAX_HEIGHT:="128"}
             STPKG_TRUST_SOURCE=${STPKG_TRUST_SOURCE:="no"}
             STPKG_GENERATE_PREVIEW=${STPKG_GENERATE_PREVIEW:="no"}
-            STPKG_IMAGE_TARGET_FILETYPE=${STPKG_IMAGE_TARGET_FILETYPE:="png"}
-            STPKG_ANIMATED_TARGET_FILETYPE=${STPKG_ANIMATED_TARGET_FILETYPE:="gif"}
+            STPKG_IMAGE_TARGET_FILETYPE=${STPKG_IMAGE_TARGET_FILETYPE:="image/png"}
+            STPKG_ANIMATED_TARGET_FILETYPE=${STPKG_ANIMATED_TARGET_FILETYPE:="image/gif"}
 
             ;;&