Bump mtl upper bounds

Author: hamishmack

vcsgui/vcsgui.cabal

@@ -69,7 +69,7 @@ executable vcsgui
                filepath >=1.2.0.0 && < 1.4,
                base >=4.0.0.0 && <4.8,
                directory >=1.1.0.0 && <1.3,
-               mtl >=2.0.1.0 && <2.2,
+               mtl >=2.0.1.0 && <2.3,
                vcswrapper ==0.1.0,
                process >=1.0.1.5 && <1.3,
                text -any
@@ -99,7 +99,7 @@ executable vcsgui-askpass
                filepath >=1.2.0.0 && < 1.4,
                base >=4.0.0.0 && <4.8,
                directory >=1.1.0.0 && <1.3,
-               mtl >=2.0.1.0 && <2.2,
+               mtl >=2.0.1.0 && <2.3,
                vcswrapper ==0.1.0,
                process >=1.0.1.5 && <1.3,
                text -any