treewide: Per RFC45, remove all unquoted URLs

pkgs/development/compilers/rust/binary.nix

@@ -25,7 +25,7 @@ rec {
     inherit src;
 
     meta = with stdenv.lib; {
-      homepage = http://www.rust-lang.org/;
+      homepage = "http://www.rust-lang.org/";
       description = "A safe, concurrent, practical language";
       maintainers = with maintainers; [ qknight ];
       license = [ licenses.mit licenses.asl20 ];
@@ -71,7 +71,7 @@ rec {
     inherit src;
 
     meta = with stdenv.lib; {
-      homepage = http://www.rust-lang.org/;
+      homepage = "http://www.rust-lang.org/";
       description = "A safe, concurrent, practical language";
       maintainers = with maintainers; [ qknight ];
       license = [ licenses.mit licenses.asl20 ];

pkgs/development/compilers/rust/cargo.nix

@@ -51,7 +51,7 @@ rustPlatform.buildRustPackage {
   doCheck = false;
 
   meta = with stdenv.lib; {
-    homepage = https://crates.io;
+    homepage = "https://crates.io";
     description = "Downloads your Rust project's dependencies and builds your project";
     maintainers = with maintainers; [ retrry ];
     license = [ licenses.mit licenses.asl20 ];

pkgs/development/compilers/rust/rustfmt.nix

@@ -25,7 +25,7 @@ rustPlatform.buildRustPackage rec {
 
   meta = with stdenv.lib; {
     description = "A tool for formatting Rust code according to style guidelines";
-    homepage = https://github.com/rust-lang-nursery/rustfmt;
+    homepage = "https://github.com/rust-lang-nursery/rustfmt";
     license = with licenses; [ mit asl20 ];
     maintainers = with maintainers; [ globin basvandijk ];
     platforms = platforms.all;