Improve About OK button look

Fixes #2151, Closes #2152

PowerEditor/src/Notepad_plus.rc

@@ -920,7 +920,7 @@ BEGIN
     LTEXT           "Home Page :",IDC_STATIC,21,59,47,8
     LTEXT           "https://notepad-plus-plus.org/",IDC_HOME_ADDR,78,59,126,8
     GROUPBOX        "GNU General Public Licence",IDC_STATIC,19,75,231,131,BS_CENTER
-    DEFPUSHBUTTON   "OK",IDOK,106,215,50,14,BS_FLAT,WS_EX_STATICEDGE
+    DEFPUSHBUTTON   "OK",IDOK,106,215,50,14,BS_FLAT
     // IDC_LICENCE_EDIT should be the last line, don't know why
     EDITTEXT        IDC_LICENCE_EDIT,31,99,209,96,ES_MULTILINE | ES_AUTOVSCROLL | ES_READONLY | NOT WS_BORDER | WS_VSCROLL
 END
@@ -933,7 +933,7 @@ FONT 8, TEXT("MS Shell Dlg"), 0, 0, 0x1
 BEGIN
     EDITTEXT        IDC_DEBUGINFO_EDIT,31,20,220,96,ES_MULTILINE | ES_AUTOVSCROLL | ES_READONLY | NOT WS_BORDER | WS_VSCROLL
 		LTEXT           "Copy debug info into clipboard",IDC_DEBUGINFO_COPYLINK,31,120,126,8
-    DEFPUSHBUTTON   "OK",IDOK,106,160,50,14,BS_FLAT,WS_EX_STATICEDGE
+    DEFPUSHBUTTON   "OK",IDOK,106,160,50,14,BS_FLAT
 END