Added a missing key constant.

--HG--
branch : minor

src/modules/event/sdl/Event.cpp

@@ -595,6 +595,7 @@ std::map<SDL_Keycode, love::keyboard::Keyboard::Key> Event::createKeyMap()
 	k[SDLK_EXCLAIM] = Keyboard::KEY_EXCLAIM;
 	k[SDLK_QUOTEDBL] = Keyboard::KEY_QUOTEDBL;
 	k[SDLK_HASH] = Keyboard::KEY_HASH;
+	k[SDLK_PERCENT] = Keyboard::KEY_PERCENT;
 	k[SDLK_DOLLAR] = Keyboard::KEY_DOLLAR;
 	k[SDLK_AMPERSAND] = Keyboard::KEY_AMPERSAND;
 	k[SDLK_QUOTE] = Keyboard::KEY_QUOTE;

src/modules/keyboard/Keyboard.cpp

@@ -59,6 +59,7 @@ StringMap<Keyboard::Key, Keyboard::KEY_MAX_ENUM>::Entry Keyboard::keyEntries[] =
 	{"!", Keyboard::KEY_EXCLAIM},
 	{"\"", Keyboard::KEY_QUOTEDBL},
 	{"#", Keyboard::KEY_HASH},
+	{"%", Keyboard::KEY_PERCENT},
 	{"$", Keyboard::KEY_DOLLAR},
 	{"&", Keyboard::KEY_AMPERSAND},
 	{"'", Keyboard::KEY_QUOTE},

src/modules/keyboard/sdl/Keyboard.cpp

@@ -170,6 +170,7 @@ const SDL_Keycode *Keyboard::createKeyMap()
 	k[Keyboard::KEY_EXCLAIM] = SDLK_EXCLAIM;
 	k[Keyboard::KEY_QUOTEDBL] = SDLK_QUOTEDBL;
 	k[Keyboard::KEY_HASH] = SDLK_HASH;
+	k[Keyboard::KEY_PERCENT] = SDLK_PERCENT;
 	k[Keyboard::KEY_DOLLAR] = SDLK_DOLLAR;
 	k[Keyboard::KEY_AMPERSAND] = SDLK_AMPERSAND;
 	k[Keyboard::KEY_QUOTE] = SDLK_QUOTE;