Fixed a few minor hunspell leaks

src/Forms/Main.cs

@@ -5836,6 +5836,7 @@ namespace Nikse.SubtitleEdit.Forms
 
                         if (result == DialogResult.No)
                         {
+                            _spellCheckForm.Dispose();
                             _spellCheckForm = new SpellCheck();
                             _spellCheckForm.DoSpellCheck(autoDetect, _subtitle, dictionaryFolder, this, startFromLine);
                         }

src/Forms/SpellCheck.Designer.cs

@@ -7,19 +7,6 @@
         /// </summary>
         private System.ComponentModel.IContainer components = null;       
 
-        /// <summary>
-        /// Clean up any resources being used.
-        /// </summary>
-        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
-        protected override void Dispose(bool disposing)
-        {
-            if (disposing && (components != null))
-            {
-                components.Dispose();
-            }
-            base.Dispose(disposing);
-        }
-
         #region Windows Form Designer generated code
 
         /// <summary>

src/Forms/SpellCheck.cs

@@ -320,6 +320,8 @@ namespace Nikse.SubtitleEdit.Forms
         private void LoadHunspell(string dictionary)
         {
             _currentDictionary = dictionary;
+            if (_hunspell != null)
+                _hunspell.Dispose();
             _hunspell = Hunspell.GetHunspell(dictionary);
         }
 
@@ -1292,5 +1294,23 @@ namespace Nikse.SubtitleEdit.Forms
             PrepareNextWord();
         }
 
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                if (_hunspell != null)
+                {
+                    _hunspell.Dispose();
+                    _hunspell = null;
+                }
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
     }
 }