cargo: update dependencies, rebuild

Both cargo and cargo-stage1 link with libssh2.  Previously
a dependency on libssh2 was only declared for cargo-stage1.
This allowed cargo to build properly (because of the build
dependency on cargo-stage1) but in situations where the
pre-built cargo archive was being activated by another
port (e.g. librsvg) a build error might occur if the cargo
binary was executed and libssh2 was not otherwise installed and active.

  cargo build --verbose  --release
  dyld: Library not loaded: /opt/local/lib/libssh2.1.dylib
  Referenced from: /opt/local/bin/cargo
  Reason: image not found

Closes https://trac.macports.org/ticket/57214

devel/cargo/Portfile

@@ -10,7 +10,7 @@ if {${subport} ne "${name}-bootstrap"} {
 }
 PortGroup           cargo 1.0
 
-#revision            0
+revision            1
 categories          devel
 platforms           darwin
 supported_archs     i386 x86_64
@@ -34,6 +34,7 @@ if {${subport} ne "${name}-bootstrap"} {
 
     depends_lib     path:lib/libssl.dylib:openssl \
                     port:curl \
+                    port:libssh2 \
                     port:rust
 
     checksums       ${distname}${extract.suffix} \
@@ -168,9 +169,7 @@ if {${subport} ne "${name}-bootstrap"} {
 
 subport ${name}-bootstrap {}
 
-subport ${name}-stage1 {
-    depends_lib-append port:libssh2
-}
+subport ${name}-stage1 {}
 
 if {${subport} ne "${name}-bootstrap"} {
     cargo.crates \