[gnome-builder] Use 'cargo build' rather than 'cargo rustc'

[Christian Hergert <chergert src gnome org>]

commit 19594ae3ec7a51f382a2d342453019e478f34737
Author: Nathaniel McCallum <npmccallum redhat com>
Date:   Sun Mar 1 14:22:24 2020 -0500

    Use 'cargo build' rather than 'cargo rustc'
    
    Unfortunately, 'cargo rustc' doesn't work in workspace projects.

 src/plugins/cargo/cargo_plugin.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/cargo/cargo_plugin.py b/src/plugins/cargo/cargo_plugin.py
index 6f311b274..d16bca58c 100644
--- a/src/plugins/cargo/cargo_plugin.py
+++ b/src/plugins/cargo/cargo_plugin.py
@@ -109,7 +109,7 @@ class CargoPipelineAddin(Ide.Object, Ide.PipelineAddin):
         build_launcher = pipeline.create_launcher()
         build_launcher.setenv('CARGO_TARGET_DIR', builddir, True)
         build_launcher.push_argv(cargo)
-        build_launcher.push_argv('rustc')
+        build_launcher.push_argv('build')
         build_launcher.push_argv('--manifest-path')
         build_launcher.push_argv(cargo_toml)
         build_launcher.push_argv('--message-format')
@@ -125,7 +125,7 @@ class CargoPipelineAddin(Ide.Object, Ide.PipelineAddin):
         if not config.props.debug:
             build_launcher.push_argv('--release')
 
-        # Configure Options get passed to "cargo rustc" because there is no
+        # Configure Options get passed to "cargo build" because there is no
         # equivalent "configure stage" for cargo.
         if config_opts:
             try: