Add colon to rust/static

Author: Br1ght0ne

snippets/rust-mode/static

@@ -2,4 +2,4 @@
 # name: static VAR = ...
 # key: static
 # --
-static ${1:VARNAME}${2: ${3:i32}} = ${4:value};
+static ${1:VARNAME}${2:: ${3:i32}} = ${4:value};