Fix compat example for ~0.0.3

[omus]

I happened to catch a mistake I introduced in #1237. Here's some proof:

❯ julia -e 'using Pkg; Pkg.generate("PkgE")'
  Generating  project PkgE:
    PkgE/Project.toml
    PkgE/src/PkgE.jl

❯ julia --project=. -e 'using Pkg; Pkg.develop(path="./PkgE")'
   Resolving package versions...
    Updating `/private/tmp/Project.toml`
  [4f94abc9] + PkgE v0.1.0 `PkgE`
    Updating `/private/tmp/Manifest.toml`
  [4f94abc9] + PkgE v0.1.0 `PkgE`

❯ cat >>Project.toml <<EOF

[compat]
PkgE = "~0.0.3"
EOF

❯ julia --project=. -e 'using Pkg; Pkg.develop(path="./PkgE")'  # ~0.0.3 is incompatible with 0.1.0
   Resolving package versions...
ERROR: empty intersection between [email protected] and project compatibility 0.0.3 - 0.0
...

❯ sed -i.bak 's/version = .*/version = "0.0.4"/' PkgE/Project.toml

❯ julia --project=. -e 'using Pkg; Pkg.develop(path="./PkgE")'  # ~0.0.3 is incompatible with 0.0.4
   Resolving package versions...
    Updating `/private/tmp/Project.toml`
  [4f94abc9] ~ PkgE v0.1.0 `PkgE` ⇒ v0.0.4 `PkgE`
    Updating `/private/tmp/Manifest.toml`
  [4f94abc9] ~ PkgE v0.1.0 `PkgE` ⇒ v0.0.4 `PkgE`

❯ sed -i.bak 's/version = .*/version = "0.0.999"/' PkgE/Project.toml

❯ julia --project=. -e 'using Pkg; Pkg.develop(path="./PkgE")' # ~0.0.3 is incompatible with 0.0.999
   Resolving package versions...
    Updating `/private/tmp/Project.toml`
  [d0e7ae38] ~ PkgE v0.0.4 `PkgE` ⇒ v0.0.999 `PkgE`
    Updating `/private/tmp/Manifest.toml`
  [d0e7ae38] ~ PkgE v0.0.4 `PkgE` ⇒ v0.0.999 `PkgE`