Fix an issue where Ctrl-*-A and Ctrl-*-Z keybindings were not properly detected

NEWS

@@ -7,6 +7,7 @@ DFHack Future
         More build information available in plugins
         Fixed a rare overflow issue that could cause crashes on Linux and OS X
         Stopped DF window from receiving input when unfocused on OS X
+        Fixed issues with keybindings involving Ctrl-A and Ctrl-Z
     Lua
         Scripts can be enabled with the built-in enable/disable commands
         A new function, reqscript(), is available as a safer alternative to script_environment()

library/Core.cpp

@@ -1917,7 +1917,7 @@ int UnicodeAwareSym(const SDL::KeyboardEvent& ke)
     }
 
     // convert A-Z to their a-z counterparts:
-    if('A' < unicode && unicode < 'Z')
+    if('A' <= unicode && unicode <= 'Z')
     {
         unicode += 'a' - 'A';
     }