replace alpha channel error message fixed

src/com/jpexs/decompiler/flash/gui/MainPanel.java

@@ -2611,7 +2611,7 @@ public final class MainPanel extends JPanel implements TreeSelectionListener, Se
                         SWF swf = it.getSwf();
                         swf.clearImageCache();
                     } catch (IOException ex) {
-                        logger.log(Level.SEVERE, "Invalid image", ex);
+                        logger.log(Level.SEVERE, "Invalid alpha channel data", ex);
                         View.showMessageDialog(null, translate("error.image.invalid"), translate("error"), JOptionPane.ERROR_MESSAGE);
                     }
 

src/com/jpexs/decompiler/flash/gui/locales/MainFrame.properties

@@ -625,3 +625,4 @@ import.script.result = %count% scripts imported.
 import.script.as12warning = Import script can import only AS1/2 scripts.
 
 error.constantPoolTooBig = Constant pool is too big. index=%index%, size=%size%
+error.image.alpha.invalid = Invalid alpha channel data.

src/com/jpexs/decompiler/flash/gui/locales/MainFrame_hu.properties

@@ -624,3 +624,4 @@ import.script.result = %count% szkript import\u00e1lva.
 import.script.as12warning = A szkript import\u00e1l\u00e1s csak AS1/2 szkriptekre m\u0171k\u00f6dik.
 
 error.constantPoolTooBig = Karakter l\u00e1nc t\u00e1rol\u00f3 t\u00fal nagy. index=%index%, m\u00e9ret=%size%
+error.image.alpha.invalid = \u00c9rv\u00e9nytelen alfa csatorna adat.